Water Resource Assessments for Without Development and Baseline Conditions

Murray-Darling Basin Authority Technical Report 2010/20

Supporting information for the preparation of the Guide to the Proposed Basin Plan

November 2010 Published by Murray–Darling Basin Authority

Postal address GPO Box 1801, Canberra ACT 2601 Office location Level 4, 51 Allara Street, Canberra City Australian Capital Territory Telephone (02) 6279 0100 international + 61 2 6279 0100 Facsimile (02) 6248 8053 international + 61 2 6248 8053 Email [email protected] Internet http://www.mdba.gov.au

Acknowledgements

This report was prepared by the Basin Plan Modelling section of the Murray-Darling Basin Authority (MDBA) based on modelling conducted by the MDBA. The modelling used MDBA models for the River Murray together with models provided by the Victorian Department of Sustainability and Environment, the New South Wales Office of Water (Department of Environment, Climate Change and Water), the Queensland Department of Environment and Resource Management, CSIRO and Snowy Hydro Ltd. The modelling was undertaken in the Integrated River System Modelling Framework initially developed by CSIRO in the Murray-Darling Basin Sustainable Yields Project and further developed by CSIRO for MDBA for Basin Plan modelling. The water availability assessment for climate change scenarios are based on climate scaling work undertaken by CSIRO for MDBA.

© Copyright Commonwealth of Australia 2010. This work is copyright. With the exception of the photographs, any logo or emblem, and any trademarks, the work may be stored, retrieved and reproduced in whole or in part, provided that it is not sold or used for commercial benefit. Any reproduction of information from this work must acknowledge the Murray–Darling Basin Authority, the Commonwealth of Australia or the relevant third party, as appropriate, as the owner of copyright in any selected material or information. Apart from any use permitted under the Copyright Act 1968 (Cth) or above, no part of this work may be reproduced by any process without prior written permission from the Commonwealth. Requests and inquiries concerning reproduction and rights should be addressed to the Commonwealth Copyright Administration, Attorney General’s Department, National Circuit, Barton ACT 2600 or posted at http://www.ag.gov.au/cca.

Disclaimer

This document has been prepared by the Murray-Darling Basin Authority for Technical users with good understanding of strengths and limitations of mathematical modelling, hydrological data and its analysis and interpretation. The information in the report also uses software and data provided by other agencies. The Authority and these agencies give no warranty for the data or the software (including its accuracy, reliability, completeness, currency or suitability) and accept no liability for any loss, damage or costs (including consequential damage) incurred in any way (including but not limited to that arising from negligence) in connection with any use or reliance on the data.

The opinions, comments and analysis (including those of third parties) expressed in this document are for information purposes only. This document does not indicate the Murray-Darling Basin Authority’s commitment to undertake or implement a particular course of action, and should not be relied upon in relation to any particular action or decision taken. Users should note that developments in Commonwealth policy, input from consultation and other circumstances may result in changes to the approaches set out in this document.

CONTENTS

1 Introduction...... 5 1.1 Background ...... 5 1.2 Scope of this report ...... 5 2 Climate Scenarios ...... 6 2.1 Historical Climate scenario ...... 6 2.2 Climate Change Scenarios ...... 7 3 Water Balance Terms ...... 8 4 Without Development and Baseline Scenarios...... 9 4.1 Paroo ...... 10 4.1.1 Model Description ...... 10 4.1.2 Results and Discussion ...... 10 4.2 Warrego ...... 12 4.2.1 Model Description ...... 12 4.2.2 Results and Discussion ...... 13 4.3 Nebine ...... 15 4.3.1 Model Description ...... 15 4.3.2 Results and Discussion ...... 15 4.4 Condamine-Balonne ...... 16 4.4.1 Model Description ...... 16 4.4.2 Results and Discussion ...... 21 4.5 Moonie ...... 23 4.5.1 Model Description ...... 23 4.5.2 Results and Discussion ...... 23 4.6 Border Rivers including Macintyre Brook ...... 24 4.6.1 Model Description ...... 24 4.6.2 Results and Discussion ...... 26 4.7 Gwydir ...... 27 4.7.1 Model Description ...... 27 4.7.2 Results and Discussion ...... 29

4.8 Namoi ...... 29 4.8.1 Model Description ...... 29 4.8.2 Results and Discussion ...... 31 4.9 Macquarie-Castlereagh and Bogan Rivers ...... 33 4.9.1 Model Description ...... 33 4.9.2 Results and Discussion ...... 33 4.10 Barwon-Darling ...... 34 4.10.1 Model Description ...... 34 4.10.2 Results and Discussion ...... 36 4.11 Lachlan...... 36 4.11.1 Model Description ...... 36 4.11.2 Results and Discussion ...... 39 4.12 Murrumbidgee ...... 41 4.12.1 Model Description ...... 41 4.12.2 Results and Discussion ...... 42 4.13 Ovens ...... 44 4.13.1 Model Description ...... 44 4.13.2 Results and Discussion ...... 44 4.14 Goulburn-Broken, Campaspe and Loddon Rivers ...... 47 4.14.1 Model Description ...... 47 4.14.2 Results and Discussion ...... 48 4.15 Wimmera ...... 50 4.15.1 Model Description ...... 50 4.15.2 Results and Discussion ...... 54 4.16 Murray ...... 56 4.16.1 Model Description ...... 56 4.16.2 Results and Discussion ...... 59

5 Whole of Basin ...... 61 6 Accounting for unmodelled inflows and diversions for preparation of the Guide ...... 64 7 Published Numbers ...... 70 8 Conclusions...... 71 9 References ...... 73 Appendix 1 Modelled diversions and end of system flows as percentage of inflows, for baseline scenarios with historical and 2030 dry, median and wet climate...... 78

LIST OF TABLES

TABLE 1 WATER BALANCES FOR THE PAROO SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 11

TABLE 2 WATER BALANCES FOR THE WARREGO SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 14

TABLE 3 WATER BALANCES FOR THE NEBINE SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 17

TABLE 4 WATER BALANCES FOR THE CONDAMINE-BALONNE SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 22

TABLE 5 WATER BALANCES FOR THE MOONIE SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 25

TABLE 6 WATER BALANCES FOR THE BORDER RIVERS & MACINTYRE BROOK SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 28

TABLE 7 WATER BALANCES FOR THE GWYDIR SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 30

TABLE 8 WATER BALANCES FOR THE NAMOI AND PEEL SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 32

TABLE 9 WATER BALANCES FOR THE MACQUARIE-CASTLEREAGH AND BOGAN RIVER SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 35

TABLE 10 WATER BALANCES FOR THE BARWON-DARLING SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 37

TABLE 11 WATER BALANCES FOR THE LACHLAN SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 40

TABLE 12 WATER BALANCES FOR THE MURRUMBIDGEE SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 43

TABLE 13 WATER BALANCES FOR THE OVENS SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS (FOR PERIOD FROM JULY 1895 TO DECEMBER 2008). 46

TABLE 14 WATER BALANCES FOR THE GOULBURN-BROKEN SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 51

TABLE 15 WATER BALANCES FOR THE CAMPASPE SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 52

TABLE 16 WATER BALANCES FOR THE LODDON SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 53

TABLE 17 WATER BALANCES FOR THE WIMMERA SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 55

TABLE 18 TLM WATER RECOVERY PROJECTS 58

TABLE 19 SNOWY WATER RECOVERY AND ENTITLEMENT 59

TABLE 20 WATER BALANCES FOR THE MURRAY SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS 60

TABLE 21 WATER BALANCE FOR WHOLE OF MURRAY DARLING BASIN FOR PREDEVELOPMENT AND BASELINE SCENARIOS 62

TABLE 22 SUMMARY OF WITHOUT DEVELOPMENT INFLOWS FOR HISTORICAL CLIMATE AND ESTIMATED % CHANGE FOR DRY, MEDIAN AND WET CLIMATE CHANGE SCENARIOS. 63

TABLE 23 SUMMARY OF BASELINE DIVERSIONS AND END OF SYSTEM FLOWS EXPRESSED AS PERCENTAGE OF INFLOWS FOR THE CORRESPONDING BASELINE CLIMATE SCENARIO. YELLOW REPRESENTS AN INCREASE AND BLUE A DECREASE COMPARED TO THE HISTORICAL CLIMATE SCEARIO. 63

TABLE 24 MODELLED WITHOUT DEVELOPMENT LOCAL INFLOWS AND ADJUSTMENTS MADE TO DETERMINE TOTAL INFLOWS (AS REPORTED IN THE GUIDE TO THE BASIN PLAN), (ALL FIGURES ARE IN GL/Y). 68

TABLE 25 MODELLED DIVERSIONS AND ADJUSTMENTS MADE TO DETERMINE THE TOTAL WATER COURSE DIVERSIONS FOR THE CURRENT DIVERSIONS LIMITS (CDL WCDS) AS DESCRIBED IN THE GUIDE (MDBA, 2010B) 69

1 INTRODUCTION

1.1 BACKGROUND

In 2007–2008, the CSIRO Murray-Darling Basin Sustainable Yields (MDBSY) project published a series of reports documenting water availability across the Murray-Darling Basin, including an assessment of the likely impacts of climate change to ~2030 on water availability (e.g. CSIRO, 2008k). This assessment was the most comprehensive and integrated assessment of water availability ever undertaken for the Murray-Darling Basin. As part of technical work supporting the development of the Basin Plan, the Murray-Darling Basin Authority (MDBA) (with assistance from CSIRO and its consultants and state governments) has developed Basin wide modelling capability in the MDBA Office by linking 24 river valley models developed by State agencies, CSIRO, Snowy Hydro Limited and MDBA in an Integrated River System Modelling Framework (Figure 1).

An understanding of water balances under various scenarios is critical information for the development of a basin plan. This report presents updates of the water balances presented by CSIRO in the MDBSY reports (CSIRO, 2007a-e, 2008a-m). The water balances presented in this report are only for the systems for which models have been developed by States, CSIRO, Snowy Hydro Limited or MDBA and have been used over the years for water management and policy development. Without Development conditions are based on current catchment conditions with all infrastructures and demands removed.

1.2 SCOPE OF THIS REPORT

This report presents resulting water balances for Without Development and Baseline Conditions under historic climate and three climate change scenarios corresponding to 2030 Dry, Median and Wet climate change scenarios. This data has been used to inform the development of the Guide to the Proposed Basin Plan. However, the numbers presented in the water balance tables for individual river valleys may not be exactly the same as the numbers presented in the Guide. Inflows, diversions and interceptions that are not included in the models have been accounted for separately in the development of the Guide to the Proposed Basin Plan. Section 6 of this report provides details on how the numbers presented in Appendix C of the Guide to the Proposed Basin Plan (Volume 1) have been derived from the model outputs. Section 7 explains why numbers reported in the water balances in this report may differ from numbers in other previously published reports.

FIGURE 1 THE RESIONS OF THE MURRAY DARLING BASIN WITH A SCHEMATIC OVERVIEW OF THE MODELS AND THEIR LINKAGES (AS FOR WITHOUT DEVELOPMENT SCENARIO)

2 CLIMATE SCENARIOS

2.1 HISTORICAL CLIMATE SCENARIO

For the water balance assessments, the historical climate scenario is defined as the period from July 1895 to June 2009. This is based on best estimates of the actual climatic conditions across the Basin for this historical period. Evaporation, rainfall and river inflows are inputs to the river system models. These data are based on recorded data, but as comprehensive records of these variables do not exist across the entire Basin and for the whole historical period, the actual data used are composite data sets that combine observations with modelled estimates of these variables. River inflow data for ungauged periods and for ungauged subcatchments have been extended both temporally and spatially

6 by either using rainfall-runoff models or statistical methods, based on available rainfall, temperature, potential evapo-transpiration and streamflow data.

Importantly, rainfall-runoff models are typically calibrated to observed streamflow over the last three to four decades, and thus the relationship derived between climate and runoff (and thus streamflow) reflects the catchment conditions over this calibration period. Calibration sub-catchments for rainfall-runoff modelling are selected to ensure the observed streamflow records are “unimpaired”, i.e. they are not affected by significant local water extraction and are reasonably stationary with respect to major changes in catchment land use (including interception activities such as farm dams). Nonetheless, catchment conditions during these calibration periods typically reflect post-catchment clearing for agriculture across much of the Basin. The modelled runoff and thus river inflows are therefore not representative of pre-European settlement conditions (for which in any case there are no streamflow measurements).

Model development, including input data development and model calibration are discussed in greater detail in separate reports for each river system, which will be referenced in this document.

2.2 CLIMATE CHANGE SCENARIOS

The climate change scenarios considered in these water availability assessments are those selected for use in the development of the Basin Plan, based on advice provided to MDBA by CSIRO (Chiew et al., 2009a). The three future climate scenarios are analogous to the climate scenarios used in the MDBSY project. The derivation of these MDBSY scenarios is described in detail in CSIRO (2008a). For Basin Plan work these scenarios have been updated and improved for MDBA by CSIRO. A short summary of the method is provided below, followed by a description and explanation of the major differences and improvements relative to MDBSY.

The daily climate series for the climate change scenarios were obtained using the daily scaling method that considers potential changes to the daily rainfall distribution and seasonal means. The method scales the historical daily rainfall and monthly PET sequences and is informed by 15 global climate models (GCMs) and three global warming scenarios from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (4AR) (IPCC, 2007). The method considers the range of local/regional future rainfall projections from the 15 GCMs for a low, mid and high 2030 global warming scenario (0.7oC, 1.0oC and 1.3oC, relative to 1990). This range of global warming mainly reflects the sensitivity of global climate to anthropogenic greenhouse gas (GHG) concentrations. There is little difference in the projected global warming for different GHG emission scenarios by 2030, but beyond 2050 the degree of global warming is far more dependent on emission scenario.

The selection of median, dry and wet extreme results presented here (see Section 4) was based on the future mean annual runoff produced by the SIMHYD rainfall-runoff model, averaged over each of the 18 MDBSY modelling regions. The “median” scenario is the median of the 15 simulations (rainfall-runoff modelling informed by projections from the 15 GCMs) for the mid-range global warming (1.0oC increase in global average surface air temperature by 2030 relative to 1990). The “dry extreme” result and the “wet extreme” are the second driest (in terms of mean annual runoff) simulation and second wettest simulation, respectively, of the 15 simulations. In the method used here, the driest and wettest modelling results both result from the high global warming scenario (1.3oC increase in global temperature).

The method used is very similar to the MDBSY methods (Chiew et al., 2008a 2008b) and South Eastern Australian Climate Initiative (SEACI) (Post et al., 2008), as described and assessed scientifically in Chiew et al. (2009b). The main differences between the MDBSY methods and the updated water availability assessment method used here are: i. Modelling for the updated assessment has been extended to June 2009 (the MDBSY modelling ends in December 2006) ii. Rainfall-runoff model calibration and regionalisation to predict runoff in gauged and ungauged areas across the Murray-Darling Basin (more than 40,000 ~5 km grid cells) has been improved in the updated assessment (in particular to reduce bias in long- term mean estimates) (Viney et al., 2009; Vaze et al., 2010). iii. The low, mid and high global warming scenarios used in the updated assessment are 0.7oC, 1.0 oC and 1.3oC respectively compared to 0.45oC, 1.03 oC and 1.60oC used in the MDBSY project.

The differences in the future rainfall and runoff simulations relative to the historical rainfall and runoff, in the updated assessment and in MDBSY caused by (i) and (ii) are marginal. The global warming range used in MDBSY takes into account carbon cycle feedbacks based on extrapolation to 2100 (CSIRO & BoM, 2007). For projections to 2030, the IPCC range of 0.7oC to 1.3oC is more realistic and has been used in subsequent Sustainable Yields projects (southwest Western Australia and Tasmania). The more realistic global warming scenario used in the updated assessment (iii) also gives similar median result, but a less dry extreme dry result and a less wet extreme wet result compared to MDBSY (by about 10 to 20 percent).

3 WATER BALANCE TERMS

In the following sections, water balances are presented for the 18 river systems and for the Basin as a whole. The water balance terms have been presented as:

1. Change in Storage - Net change in storage (dams and river channel) between the start of simulation in July 1895 and end of simulation in June 2009. 2. Inflows - Total system inflows from gauged and ungauged tributaries (and where relevant from modelled tributaries). 3. Losses - Total system losses including evaporation losses, river channel losses and anabranches that do not return to the river or the downstream river system, e.g. flow to terminal lakes or wetlands. 4. Diversions - Total diversions from the modelled system, which are accountable under the MDB Cap. 5. Outflows – The End of System flow is the flow from the modelled area to a downstream model, or to the sea in the case of the Murray system. For some models, the reported ‘total modelled outflows’ may include other outflows (e.g. flood breakouts) that need to be taken into account for the calculation of the unattributed flux (or mass balance error).

In the water balance tables, results for climate change scenarios (for both Without Development and Baseline scenarios) have been presented as percentage change compared to the historical climate scenario. Appendix 1 summarises Baseline diversions and end of system flows as a percentage of total system inflows for all river systems. This has been presented in order to highlight relative differences in the proportion of inflows that is used for local diversions, and the proportion that flows to the Barwon-Darling and Murray systems under climate change.

These water balances provide our best knowledge of the volumes of water that flow into our river systems, volumes used for consumptive use, volumes flowing into floodplain wetlands, volumes lost as recharges to groundwater or evaporation and the volumes that reach the end of system. Although in the MDBSY studies results for water balances were presented, water availability for river valleys was defined as the streamflow at the gauge on an upstream-downstream river transect, where streamflow is greatest, i.e. the “point of maximum flow” under “Without Development” conditions. MDBA has adopted another approach, whereby total system inflows have been used to assess volume of water available for use. MDBA has used the best available information on system water balances for deriving sustainable diversion limits for the Basin Plan.

4 WITHOUT DEVELOPMENT AND BASELINE SCENARIOS

The following sections present the key features of the individual Without Development and Baseline models and the water balance results for Without Development and Baseline scenarios, under historical conditions and under the 2030 Dry, Median and Wet climate change scenarios.

4.1 PAROO

4.1.1 MODEL DESCRIPTION

The Paroo River is an ephemeral river, with most of its catchment located in Queensland. The Paroo region covers less than 4% of the total area of the Murray Darling Basin, and has less than 0.1% of the basin’s population (CSIRO, 2007c).

The Paroo river system is modelled with an IQQM model (DLWC, 1995) representing the Paroo River from the Yarronvale gauge (424202) to its inflow into Darling River. Whilst the Queensland Department of Environment and Resource Management (DERM) has included diversions and residual inflows into the NSW portions of the Paroo, Warrego, Nebine and Moonie IQQMs, DERM considers these representations to be indicative only and advises they should not be relied upon without further verification by the NSW’s Office of Water (NOW). The Paroo system rarely flows to the Barwon-Darling system and in absence of enough data to calibrate the river system model; the inflows from Paroo system to the Barwon-Darling system are assumed to be zero.

The Baseline Conditions for the Paroo system are based on the Resource Operations Plan (DERM, 2006a). This Resource Operations Plan model version is described in detail in DERM (2006b). No changes have been made to the model for its integration in the Integrated River Systems Modelling Framework of MDBA. The model was audited by Bewsher Consulting (Bewsher, 2010) for its use for Cap Auditing and was recommended for use for Annual Cap Auditing. The audit identified issues with the approximate nature of data available to model overland flows and recommended to submit a revised model by December 2012.

4.1.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Paroo system are summarised in Table 1. The Paroo system does not have too many flow gauges, therefore only 8% of the river system inflows are measured inflows and rest of 82% are estimated using models. The total mean annual inflow to the Paroo system is estimated at 678.2 GL/yr under Without Development Conditions. Under climate change, the total inflows in the Paroo system are estimated to range from a decrease of 18% and an increase of 30% under the Dry 2030 and wet 2030 climate change scenarios, with a decrease of 1% under the median climate change scenario.

The Paroo system has only a very small amount of diversions and is still in pristine condition (0.04% of total inflows). Consequently, the impact of climate change on diversions is likely to be negligible and all impact of climate change within the system will be borne by the environment.

TABLE 1 WATER BALANCES FOR THE PAROO SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage -1.0 5.6 0.1 -6.4 -1.0 5.6 0.1 -6.4 Inflows Directly gauged (not included in water balance) 56.6 -7.4 -3.1 31.0 56.6 -7.4 -3.1 31.0 Indirectly gauged 621.5 -19.0 -0.9 29.8 618.7 -18.9 -0.8 29.7 Total inflows 678.2 -18.1 -1.0 29.9 675.4 -17.9 -1.0 29.8 Diversions QLD Diversions Unregulated off-allocation (including S&D) - - - - 0.06 0.2 0.2 0.6 Unregulated floodplain harvesting ------High security Hungerford TWS - - - - 0.13 0.0 0.0 0.0 Total QLD Diversions - - - - 0.19 0.1 0.1 0.2 NSW Diversions Unregulated off-allocation (including TWS) - - - - 0.10 0.0 0.0 0.0 Unregulated floodplain harvesting ------Total NSW Diversions - - - - 0.10 0.0 0.0 0.0 Total Diversions - - - - 0.29 0.0 0.0 0.1 Losses Net evaporation from Storage 126.9 -5.4 -0.5 8.4 126.9 -5.4 -0.5 8.4 Natural water bodies 492.4 -19.5 -2.1 30.7 489.4 -19.3 -2.0 30.5 Losses to Barwon-Darling 59.4 -33.0 6.4 69.2 59.3 -33.0 6.4 69.1 Total Losses 678.8 -18.0 -1.0 29.9 675.6 -17.9 -1.0 29.8 Outflows Wanaaring EOS flow 327.4 -23.5 0.3 42.1 327.2 -23.5 0.3 42.1 Wilcannia EOS flow 59.4 -33.0 6.4 69.2 59.3 -33.0 6.4 69.1 QLD to NSW Border flow 475.6 -19.7 -1.8 33.1 475.4 -19.8 -1.8 33.1 Total Outflow to Barwon-Darling 0 0 0 0 0 0 0 0 Unattributed Flux (GL) - Water Balance [Diversions for QLD only] Total Unattributed Flux (GL) 0.4 - - - 0.4 - - -

4.2 WARREGO

4.2.1 MODEL DESCRIPTION

The Warrego region covers 7 percent of the Murray Darling Basin and is predominantly located in Queensland at the northern edge of the basin. It is bounded to the east by the Condamine-Balonne region and by the Paroo region to the west. The region has less than 1% of the basin’s population (CSIRO, 2007d).

The Warrego River system is modelled using a daily time step IQQM (Old DOS version) developed by the Queensland Department of Environment and Resource Management (DERM, 2006c). The model simulates the Warrego River system from the Augathella gauge (423204) to three terminal points:

1. Ford’s Bridge (423001) draining to Darling system (Node 63) 2. Widgeegoara-Noorama Creeks draining to Nebine Creek (Node 380) 3. Cuttaburra Creek draining to Paroo system (Node 108)

The Warrego system in Queensland crosses the border into NSW at following points:

1. Barringun - 423003 (Node 25) 2. Widgeegoara-Noorama Creeks at the border (Node 380) 3. Irrara Creek at the border (Node 381) 4. Cuttaburra Creek at the border (Node 382)

Allan Tannock Weir is the only regulated storage in the model. The model assumes that inflows into Allan Tannock Weir up to 300 ML/day will bypass the weir. There is a regulated water supply from Allan Tannock Weir to two irrigation nodes. The water is shared between these users via an annual accounting system.

The Without Development and Baseline versions of the model provided by the Queensland DERM were developed for the Resource Operations Plan for the Warrego (DERM, 2006a). No changes have been made to the model for its integration in the Integrated River Systems Modelling Framework of MDBA, so the model is directly based on the Resource Operations Plan version, which is described in detail in DERM (2006c). The model was audited by Bewsher Consulting (Bewsher, 2010) for its use for Cap Auditing and was recommended for use for Annual Cap Auditing. The audit identified issues with the approximate nature of data available to model overland flows and recommended that DERM, Queensland submit a revised model by December 2012 after suggested improvements to the model.

4.2.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Warrego system are summarised in Table 2

The Warrego system does not have many flow gauges, therefore only 8% of the river system inflows are measured inflows and the remaining 82% are estimated using models. The total inflows in the Warrego system are 616 GL/yr and are expected to change between a decrease of 24% and an increase of 33% under the Dry 2030 and Wet 2030 climate change scenarios, with a decrease of 3% under the Median climate change scenario. The Warrego system has only a small fraction of inflows being diverted from the river system (8% of total inflows). Under Without Development Conditions, 15% of the total inflows would reach the Barwon-Darling system. This has decreased to 12% under Baseline Conditions.

TABLE 2 WATER BALANCES FOR THE WARREGO SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage -0.35 46.4 44.9 -29.2 -0.38 53.3 53.6 -24.4 Inflows Directly gauged 51.0 -22.8 20.3 40.7 51.0 -22.8 20.3 40.7 Indirectly gauged 565.1 -24.3 -5.2 -5.2 565.1 -24.4 -5.2 32.6 Total inflows 616.1 -24.2 -3.1 -3.1 616.1 -24.2 -3.1 33.3 Diversions Licensed private diverters QLD regulated diversions - - - - 2.5 -0.5 -0.4 0.2 QLD unregulated access - - - - 42.1 -15.4 -5.0 16.2 QLD floodplain harvesting ------QLD stock and domestic - - - - 0.10 1.3 1.2 1.6 Total QLD Diversions - - - - 44.7 -14.5 -4.8 15.3 CEWH entitlement - - - - 7.4 -12.6 -3.0 15.0 NSW unregulated off allocation access - - - - 6.9 -2.3 -1.0 2.0 Total Diversions - - - - 51.6 -12.9 -4.3 13.5 Losses Total QLD losses 378.1 -24.5 -0.9 33.5 356.3 -25.1 -0.7 34.6 Total NSW losses 148.0 -20.3 -6.6 24.4 132.4 -22.0 -7.0 26.8 Total Losses 526.1 -23.3 -2.5 30.9 488.7 -24.2 -2.4 32.5 Outflows Fords Bridge – outflow to Barwon-Darling 69.4 -21.7 -7.7 32.6 58.2 -24.0 -8.5 36.9 Cuttaburra Creek – outflow to Paroo 17.1 -59.5 -1.9 105.5 14.3 -61.4 0.6 114.1 Norooma & Widgeegoara Creek – outfl. to Nebine 3.9 -31.7 0.4 45.8 3.7 -31.8 0.6 45.7 Total Outflows 90.4 -29.3 -6.2 47.0 76.2 -31.4 -6.3 51.8 Unattributed Flux (GL) Total Unattributed Flux (GL) 0.02 - - - 0.04 - - -

With current water sharing arrangements (i.e. as under Baseline Conditions), the impact of climate change is likely to be different for different water users. The impacts on consumptive users and end of system flows are analysed and presented in Appendix 1. Under historical climate, 8% of the total inflows is diverted for consumptive use and 12% flows into the Barwon-Darling system. Under the Median climate change scenario, these proportions are likely to remain the same. However, for the Dry climate scenario the proportion being diverted increases to 10%, while the proportion that flows to the Barwon- Darling system decreases to 11%. Under the Wet climate scenario, the proportion of inflows that is diverted may decrease to 7%, while the proportion flowing to the Barwon-Darling increases to 14%.

4.3 NEBINE

4.3.1 MODEL DESCRIPTION

The Nebine system is a sub-catchment of the Condamine-Balonne system (CSIRO, 2008c). The Nebine model is an IQQM representation of the Nebine River from the headwater inflows at Wallam Creek, Mungallala Creek and the Nebine River and includes inflows from the Warrego River through the Widgeegoara and Noorama Creeks near the NSW border. The model ends at the confluence of Nebine and Warrego inflows. The outflows from the Nebine are inflows into the Lower-Balonne system. The Nebine system is unregulated and has no regulated storages, but the model includes nine storages to model the natural water bodies.

The Without Development and Baseline version of the models are provided by the Queensland Department of Environment and Resource Management and were developed for the Resource Operations Plan for the Nebine (DERM, 2006a). No changes have been made to the model for its integration in the Integrated River Systems Modelling Framework of MDBA, so the Nebine Baseline model used is the Resource Operations Plan version of the model, described in detail in DERM (2006e). The model was audited by Bewsher Consulting (Bewsher, 2010) was accredited for use for Annual Cap Auditing. The audit identified issues with the approximate nature of data available to model overland flows and recommended that DERM, Queensland submit a revised model by December 2012 after suggested improvements to the model.

4.3.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Nebine system are summarised in Table 3. The Nebine system does not have any long term gauge, so all its inflows are estimated using models. The total inflows in the Nebine system are

94 GL/yr and are estimated to change between a decrease of 31% and increase of 40% under the Dry 2030 and Wet 2030 climate change scenarios, with a decrease of 10% under the Median climate change scenario. Under Without Development Conditions, 59% of inflows reaches the Lower-Balonne system. This has decreased to 52% under Baseline Conditions, with 7% of total inflows being diverted.

With current water sharing arrangements, the impact of climate change is likely to be different for different water users. The impacts on consumptive users and end of system flows are analysed and presented in Appendix 1. Under historical climate, diversions are 7% of system inflows. This proportion may increase to 8% or decrease to 6% for 2030 Dry and Wet climate scenarios, while for the Median climate change scenario, it is likely to remain at the current level of 7%. The percentage of inflows that reaches the Lower-Balonne could decrease to 50% under the Dry scenario or increase to 54% under the Wet scenario and is likely to remain at current level of 52% under the 2030 Median climate change scenario.

4.4 CONDAMINE-BALONNE

4.4.1 MODEL DESCRIPTION

The Condamine-Balonne region (including the Nebine) is predominantly in southern Queensland, extends about 100 km to the south-west into New South Wales and represents 12.8 % of the total area of the MDB. It has 9% of the basin’s population (CSIRO, 2008c). The Condamine-Balonne system is modelled using four separate models that have been linked together:

1. The Upper Condamine (UCON) daily time step IQQM model 2. The Middle Condamine (MCON) daily time step IQQM model 3. The St George (STGE) daily time step Capacity Share model 4. The Lower Balonne (LBON) daily time step IQQM model

The four models have been developed by the Queensland Department of Environment and Resource Management and are described below. In this report, these models have been described in much more details as compared to other models as there is no report available with MDBA describing set up of these models for Water Resource Plan/Resource Operations Plan.

TABLE 3 WATER BALANCES FOR THE NEBINE SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Upper Condamine model The model represents the Upper Condamine River from the Condamine headwater inflows into Killarney Weir to the Condamine River at Cecil Plains Weir gauge (422316A) and the North Condamine River at the Lone Pine gauge (422345A) in Queensland. The outflows from Upper Condamine are inflows into the Middle Condamine system.

The model has eight in-stream supply storages; three unregulated (Killarney Weir, Connolly Dam and North Toolbura Weir) and five regulated (Leslie Dam, Talgai Weir, Yarramalong Weir, Lemontree Weir and Cecil Plains Weir). Off-stream storages for water and floodplain harvesting are also included in the model.

The water use modelled includes 22 median security regulated users, 95 unregulated users, five floodplain harvesters, four high security town water supplies and seven high security stock and domestic users in Queensland. The Upper Condamine system is operated under an annual accounting scheme with a maximum allocation level of 100 percent.

Middle Condamine model The model represents the Middle Condamine system from Cecil Plains Weir and Lone Pine gauge to the Beardmore Dam headwater gauge (422212B), including the Maranoa River. The outflows from Middle Condamine are inflows into the Lower Balonne model for Without Development Conditions and inflows into the St George model for the Baseline and Basin Plan Conditions.

The model has 15 regulated storages (Tipton Weir, Cooby Dam, Loudon Weir, Bell Town water supply, Jandowae town water supply, Warra Weir, Chinchilla Weir, Condamine Weir, Rileys Weir, Tara town water storage, Freers Weir, Dogwood Creek Weir, Drillham Creek Weir, Surat Weir, and Neil Turner Weir). The model also has off-stream storages for water and floodplain harvesting.

The water use modelled includes 13 median security regulated users, 108 unregulated users, five floodplain harvesters, 15 high security town water supplies and six high security stock and domestic users in Queensland. The Middle Condamine system is operated under two annual accounting schemes, both with a maximum allocation level of 100%.

St George model It should be noted that this valley model used for the Basin Plan is identical to what CSIRO used in the sustainability yields project (CSIRO, 2009c). The model’s description in this report is repeated from CSIRO (2009c) for reader’s convenience.

The St George daily model was built to simulate the St George Water Supply Scheme (WSS). The model covers a section of the Balonne River from Beardmore Dam to the St George Jack Taylor Weir gauge (422201). It receives inflows from the Middle Condamine model and provides outflows to the Lower Balonne model.

The St George WSS consists of Beardmore Dam, which is connected to Moolabah weir and Buckinbah weir by the Thuraggi Channel. The Buckinbah main channel supplies most of the demand to irrigators. Some water is released from Beardmore Dam down the Balonne River to Jack Taylor Weir. Releases are made from Jack Taylor Weir (JTW) to users downstream and water is pumped out of the weir to the St George channel to supply about 10 percent of the channel farms. There is a number of users who draw directly out of Lake Kajarabee (the lake created by Beardmore Dam) and from the section between the dam and Jack Taylor Weir. There are also some users who pump directly from Thuraggi Channel.

The Beardmore dam and the three weirs (JTW, Moolabah and Buckinbah) have been combined into a single storage for ease of modelling. The storage-area-volume curve used for the single storage is adjusted to account for the levels maintained in the weirs during normal operation of the combined storages. Included also in the model are off-stream storages for water and floodplain harvesting.

The St George WSS system is different from other water resource schemes in Queensland, as it uses an individual capacity share scheme to share the water between the various users rather than an announced allocation system. This is done by modelling individual shares in the storage. There are a total of 57 shares in the model; 13 shares representing the regulated users including the town water supply, the Sunwater share and a bulk share, 39 unregulated shares representing the water harvesters and five shares representing the overland flow harvesters. Of the 44 unregulated shares representing the water harvesters and the overland flow harvesters, 24 are upstream of JTW and 20 are Downstream of JTW to B1 bifurcation. Each share has a defined capacity, initial storage volume and percentage of the inflow. Each individual can be assigned a share along with the Sunwater share, the bulk share and the town water supply. Each share can also have on-farm storage. The model keeps a daily account of the volume in each share as it changes with inflow, evaporation and releases.

Each share’s annual use is limited to the individual share’s nominal allocation. If the use of allocation water by an individual capacity share at the end of the water year is less than 100% of the allocation, the share is allowed to carryover the unused allocation up to a limit of 20%.

Lower Balonne model

The Lower Balonne model represents the Balonne, Culgoa and Bokhara rivers from headwater inflows from the Balonne at St George and Nebine models, including Narran River and Narran Lakes. The model branches out to represent three anabranches – Culgoa, Bokhara and Narran, and ends further downstream of Collerina in Culgoa, of Goodwins in Bokhara and of Wilby Wilby in Narran. The Lower Balonne system flows into the Barwon- Darling system.

The Lower Balonne system is unregulated and has no regulated storages in the model. However, the model includes 14 storages to model the natural water bodies and has two large on-river storages that represent private water users. The model also has storages for water and floodplain harvesting, including Cubbie Station. The water use is modelled in the Queensland side of the system for unregulated users, floodplain harvesters, and two town water supplies and in the NSW side for unregulated users and three town water supplies.

Note that there is some overlap between the St. George model and the Lower-Balonne model. The St George model ends at the B1 bifurcation point downstream of JTW, whereas the Lower-Balonne model starts from JTW. This overlap is taken into account while reporting results for the Condamine-Balonne system.

The Condamine-Balonne model flows into the Barwon-Darling system at three points:

1. Downstream of Collerina gauge (422006) in Culgoa river 2. Downstream of Goodwins gauge (422005) in Bokhara river 3. Downstream of Wilby Wilby gauge (422016) at Narran Lake outflow

The Environmental flow rules in the Baseline Conditions of the St George and Lower Balonne models are:

1. Low flows: If flows have not passed through the river system for 12 months, low flow rules are applied in three stages:  Water stored in Beardmore Dam for stock and domestic needs will be released when any flow occurs after any 12 month period without flow-through  If the release appears unlikely to result in a flow-through event and the normal water harvesting flow thresholds are reached, the normal allowable take of water will be reduced to 90% for up to five days. The allowable take of water by weirs below Jack Taylor Weir will be reduced by 10% for the same period.  If a flow-through still appears unlikely, up to 10% of inflows that would usually be stored under water allocations in the St George Water Supply Scheme will be released. 2. Median flows: If a flow with a peak of at least 60,000 ML/day recorded at St George Jack Taylor Weir has not occurred for two years, or a peak of 100,000 ML/day has not occurred for three years:  The allowable water harvesting take is to be reduced to 90% for up to five days. 3. Narran Lakes filling flows: When Without Development flow patterns would fill the Narran Lake Nature Reserve Ramsar site (this applies during the winter months when bird breeding occurs):  The allowable water harvesting take under the rules will be reduced to 90% for up to ten days.  A similar restriction will apply if a flow would refill the site within four months of an initial fill.

4. Bypass flows: Following bypass flow rules apply to:  Loudon Weir: Up to 200 ML/day of inflow  Chinchilla Weir: Up to 122 ML/day when the weir is above 3170 ML  Beardmore Dam: Up to 730 ML/day of inflow

The four models for the Condamine-Balonne being used for Basin Plan modelling correspond to the Resource Operations Plan for the Condamine-Balonne (DERM, 2008c). However, no Cap model reports have been submitted for these models yet, and hence the models for the Condamine-Balonne system are yet to be audited by Bewsher Consulting for their accreditation for Cap implementation.

4.4.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Condamine- Balonne system are summarised in Table 4. The Condamine-Balonne system has a limited number of flow gauges on contributing tributaries. Consequently, only 13% of the river inflows is based on gauged data and 87% is estimated using models. The total inflows in the Condamine-Balonne system are 1706 GL/yr and are estimated to change between a decrease of 21% and an increase of 12% under the Dry and Wet 2030 climate change scenarios, with a decrease of 9% under the Median climate change scenario. Under Without Development Conditions 33% of the total inflows flows into the Barwon-Darling system. This proportion has decreased to 14% under Baseline Conditions, whereby 42% of the inflows is diverted.

With current water sharing arrangements, the impact of climate change is likely to be different for different water users. The impacts on consumptive users and end of system flows are analysed and presented in Appendix 1. Under historical climate, diversions are 42% of system inflows. This may increase to 46% or 44% under the Dry and Median climate scenario or decrease to 40% under the Wet climate scenario. On the other hand, the proportion of inflows that flows into Barwon-Darling could decrease to 13% or increase to 15% under the Dry and Wet scenarios respectively. Under the 2030 Median climate scenario, it is likely to remain at the current conditions of 14%.

TABLE 4 WATER BALANCES FOR THE CONDAMINE-BALONNE SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage -0.2 3.5 3.9 -4.3 -1.1 22.1 13.4 -12.0 Inflows Tributary inflow from Nebine 55.4 -31.5 -9.5 42.1 48.9 -33.8 -10.3 45.4 Directly gauged (headwater) 229.5 -25.3 -10.5 12.5 229.5 -25.3 -10.5 12.5 Indirectly gauged 1421.7 -20.4 -8.5 11.1 1421.9 -20.4 -8.5 11.1 Total inflows 1706.6 -21.4 -8.8 12.3 1700.4 -21.4 -8.8 12.3 Diversions QLD Diversions General security – regulated access - - - - 71.6 -5.3 -1.5 1.3 General security – unregulated access - - - - 472.0 -13.5 -4.0 6.2 Flood plain harvesting - - - - 145.8 -20.5 -9.2 14.9 Town water supply, stock and domestic - - - - 17.0 -5.4 -1.8 0.6 Total Diversions (QLD) - - - - 706.3 -13.9 -4.8 7.4 NSW Diversions Off allocation access - - - - 1.0 -0.3 0.5 3.0 Flood plain harvesting ------Town water supply, stock and domestic - - - - 0.09 -11.9 -5.2 1.1 Total Diversions (NSW) - - - - 1.1 -1.1 0.1 2.9 Total Diversions - - - - 707.4 -13.9 -4.8 7.4 Losses River losses 976.2 -23.9 -10.2 14.5 595.6 -29.7 -13.6 17.9 Net evaporation from storages 161.1 -10.5 -2.4 6.1 157.5 -13.0 -3.7 7.6 Total Losses 1137.2 -22.0 -9.1 13.4 753.1 -26.2 -11.5 15.7 Outflows Border flows 913.6 -19.7 -7.7 10.0 379.4 -28.0 -12.3 15.2 End of System Total Outflows 569.4 -20.2 -8.2 10.2 241.1 -28.5 -12.4 15.9 Unattributed Flux (GL) Total Unattributed Flux (GL) 0.2 - - - -0.06 - - -

4.5 MOONIE

4.5.1 MODEL DESCRIPTION

The Moonie region is largely in south-western Queensland to the east of St George. It covers 1.4 percent of the total area of the Murray-Darling Basin. Its population is less than 0.1 percent of the MDB total (CSIRO, 2008i).

The Moonie River system is modelled using a daily time step IQQM developed by the Queensland Department of Environment and Resource Management (DERM, 2006d). The model simulates the Moonie River system from Nindigully (417201) to Gundablouie (417001). The Moonie system in Queensland crosses the border into NSW at a point upstream of Gundablouie. There are no regulated storages in the model, but there are natural pools and water bodies along the length of the Moonie River that are modelled. The 1.2 GL/year of unallocated water described in the Moonie Water Resource Plan 2003 (DERM, 2008b) is included in the model.

The Without Development and Baseline versions of the models are provided by the Queensland DERM and were developed for the Resource Operations Plan for the Moonie (DERM, 2008b). No changes have been made to the model for its integration in the Integrated River Systems Modelling Framework of MDBA, hence the Baseline model used for the Moonie is the Resource Operations Plan version of the model, described in detail in DERM (2006d). The model was audited by Bewsher Consulting (Bewsher, 2010) and was accredited for the implementation and auditing of the Cap set by the Murray Darling Basin Ministerial Council (MDBMC). The audit identified issues with the approximate nature of data available to model overland flows and recommended to submit a revised model by December 2012.

4.5.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Moonie system are summarised in Table 5. The Moonie system has a good number of flow gauges with 75% of the river system inflows based on gauged data and only 25% estimated using models. The total inflows in the Moonie system under historical climate are 151 GL/yr and are estimated to change between a decrease of 22% and an increase of 17% under the Dry 2030 and Wet 2030 climate change scenarios, with a decrease of 10% under the Median climate change scenario. Under Without Development Conditions, the proportion of inflows that reaches the Barwon-Darling system is 47%. Under Baseline Conditions, this has been reduced to 44%, whereby 22% of total inflows is diverted.

With current water sharing arrangements, the impact of climate change is likely to be different for different water users. The impacts on consumptive users and end of system

23 flows are analysed and presented in Appendix 1. Under historical climate, 22% of system inflows is diverted. This proportion may increase to 24% or decrease to 20% for the 2030 Dry and Wet climate scenarios respectively. For the median climate change scenario, the proportion of inflows that is diverted will slightly increase from current level to 23%. On the other hand, the proportion of inflows that flows into Barwon-Darling could decrease from the current level of 47% to 44% under the Dry scenario or increase to 50% under the Wet scenario. Under the 2030 Median climate scenario, the proportion of inflows that flows into the Barwon-Darling is likely to decrease slightly to 46% of inflows, i.e. 1% increase in end of system flow will be at the expense of 1% decrease in diversions.

4.6 BORDER RIVERS INCLUDING MACINTYRE BROOK

4.6.1 MODEL DESCRIPTION

The Border Rivers region straddles the border between NSW and QLD, and covers 4% of the area of the Murray Darling Basin. The region has 2.5% of the total population of the MDB (CSIRO, 2007a). The Border Rivers and Macintyre Brook systems are modelled separately using two models.

Macintyre Brook model

The Macintyre Brooke model simulates the Macintyre Brook system from Coolmunda Dam to its confluence with the Dumaresq River. The Macintyre Brooke outflows are the total of two modelled outflows, representing the regulated and unregulated components of flow at the Booba Sands gauge (416415). Coolmunda Dam is the only regulated storage in the model, in addition to two unregulated weirs, i.e. Whetstone and Ben Dor. The model is operated under an annual accounting scheme. Water use is modelled by seven lumped demand locations corresponding to Queensland median security irrigators and town water supplies.

TABLE 5 WATER BALANCES FOR THE MOONIE SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage -0.00 1701.3 493.5 -585.2 -0.01 402.0 120.9 -119.7 Inflows QLD inflows Directly gauged 112.9 -21.6 -10.4 16.2 112.9 -21.6 -10.4 16.2 Indirectly gauged 24.2 -25.1 -10.8 17.2 24.2 -25.1 -10.8 17.2 Total QLD inflows 137.1 -22.2 -10.4 16.4 137.1 -22.2 -10.4 16.4 Total NSW inflows 14.0 -19.7 -9.7 20.9 14.0 -19.7 -9.7 20.9 Total inflows 151.1 -22.0 -10.4 16.8 151.1 -22.0 -10.4 16.8 Diversions QLD Diversions QLD unsupplemented access - - - - 30.8 -15.0 -6.4 8.2 QLD town water supply - - - - 0.6 -32.8 -17.1 34.1 Total QLD Diversions - - - - 31.4 -15.4 -6.6 8.7 CEWH entitlement - - - - 1.1 -3.7 -1.5 1.0 NSW unregulated access - - - - 0.8 -20.6 -9.1 13.1 Total Diversions - - - - 33.3 -15.1 -6.5 8.5 Losses QLD losses 39.2 -11.2 -4.8 7.8 34.0 -11.9 -5.2 8.5 NSW losses 15.6 -31.9 -15.8 26.3 11.7 -34.4 -17.9 30.6 Total Losses 54.8 -17.1 -7.9 13.1 45.7 -17.7 -8.4 14.5 Outflows QLD to NSW border flow 97.9 -26.6 -12.7 19.8 69.9 -30.8 -15.0 24.3 Gundablouie EOS flow to Barwon-Darling 96.3 -24.7 -11.8 18.9 71.4 -28.1 -13.6 22.7 Unattributed Flux (GL) Total Unattributed Flux (GL) -0.03 - - - 0.68 - - -

Border Rivers model

The Border Rivers model simulates the Border Rivers system from the headwater inflows of Pike Creek into Glenlyon Dam and the Severn River (NSW) into Pindari Dam. The water use in Queensland is modelled for median security regulated, unregulated access and town water supplies and in NSW for general security, supplementary access and high security town water supplies. NSW supplementary access is constrained by a 120 GL/yr Cap.

The natural weir pools and floodplains along the length of the Border Rivers are modelled as storages. Pindari Dam, Glenlyon Dam, and Boggabilla Weir are the regulated storages in the model. The model also includes unregulated system on-farm storage including overland flow harvesting.

The model includes state sharing of Glenlyon Dam and Boggabilla Weir. There is also state sharing of inflows and surplus flows. Surplus flows are allocated on a state basis and any underutilised water is accessible to the other state with a payback arrangement in Glenlyon Dam.

The Border Rivers model feeds in to Barwon-Darling system from three points:

1. Mungindi gauge (416001) 2. Neeworra on Boomi river (416028) 3. Confluence of Little Weir river and Barwon River

The Border Rivers Cap model is described in more detail in DERM (2008a). The Border Rivers and Macintyre Brook models are yet to be audited by Bewsher Consulting for accreditation for use for the Cap implementation. The Baseline model as used by MDBA is the model corresponding to Inter Government Agreement between NSW and QLD.

4.6.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Border Rivers system (including Macintyre Brook system) are summarised in Table 6. The system has a reasonable number of flow gauges on the contributing tributaries with 41% of the river system inflows based on gauged data, and 59% estimated using models. The total inflows for Without Development Conditions are estimated to vary between a decrease of 20% and an increase of 12% under the Dry 2030 and Wet 2030 climate change scenarios, with a decrease of 9% under the Median climate change scenario. For Baseline Conditions, total inflows vary between a decrease of 26% (2030 Dry) and an increase of 16% (2030 Wet), with a decrease of 9% for 2030 Median.

For Border Rivers system (including the Macintyre Brook system) 41% of its total inflows flows into the Barwon-Darling system under Without Development Conditions. This has decreased to 26% under Baseline Conditions, with 21% of inflows being diverted.

Under climate change scenarios with current water sharing arrangements, the impact in the system is likely to be different for different water users. The impact on consumptive users and end of system flows are analysed and presented in Appendix 1. Under Baseline Conditions with historical climate, diversions are 21% of system inflows. This proportion is expected to increase to 24% and 22% for the 2030 Dry and Median 2030 scenarios and to decrease to 19% for the Wet 2030 climate scenarios. The proportion of inflows that flows into the Barwon-Darling is could decrease, from the current level of 26%, to 23% and 22% under the 2030 Dry and Median climate scenarios, or increase to 27% under the 2030 Wet scenarios.

4.7 GWYDIR

4.7.1 MODEL DESCRIPTION

The Gwydir region is located in north-eastern NSW and covers 2 percent of MDB. It has 1.4% of the basin’s population (CSIRO, 2008e). One of the key environmental sites in the region is Gwydir wetland, which is located on the lower Gwydir River floodplain downstream of Moree and covers an area of some 100,000 ha. For regulated parts of Gwydir Catchment a daily time step IQQM model has been set up by the NSW’s Office of Water (NOW, DECCW). The Gwydir model covers the catchments of Gwydir River from Stonybatter gauge (418029) to its confluence with the Barwon River. Towards the lower end of the Gwydir Valley, the model covers the floodplains of Mehi River, Mallowa Creek, Moomin Creek and Carole/Gil Gil Creeks. The model provides three end-of-system flows to the Barwon-Darling Model, i.e. Gwydir River at Collymongle gauge (418031), Mehi River at Collarenebri gauge (418055) and Gil Gil Creek at Galloway Gauge (416052), as well as return flows from the Gingham water course. During major floods, the accuracy of measurements of flow at these gauges is poor and it is believed that some floods bypass these gauges; the estimated flow contributions due to these bypass flows are included in the Barwon-Darling model as additional floodplain flows.

The Cap model setup is described in detail in DNR (2009). There is no separate documentation of the Water Sharing version of the model, but environmental flow rules and water sharing arrangements in the model correspond to the Gwydir Water Sharing Plan (DIPNR, 2004a). The model does not include water buybacks by the Commonwealth and NSW governments since the start of the Water Sharing Plan. This Cap version of the model has been reviewed as part of the Cap Auditing (Bewsher, 2009) and has been accredited for Cap implementation.

TABLE 6 WATER BALANCES FOR THE BORDER RIVERS & MACINTYRE BROOK SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS Model Run Nos 613 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage 0.13 -27.0 -21.5 16.4 -0.26 186.7 48.1 157.8 Inflows Directly gauged (Headwater) 814.4 -26.9 -10.7 14.6 820.0 -26.8 -10.7 14.6 Indirectly gauged 1187.6 -16.0 -7.1 10.4 1187.9 -25.7 -7.8 16.5 Total inflows 2001.9 -20.4 -8.6 12.1 2007.9 -26.2 -9.0 15.7 Diversions QLD Diversions General security on-allocation - - - - 42.4 -19.3 -5.6 5.3 General security off-allocation - - - - 178.0 -16.4 -5.6 7.0 Town water supplies - - - - 2.6 -0.2 -0.1 0.0 QLD Diversions Sub-total - - - - 223.1 -16.8 -5.5 6.6 NSW Diversions General security on-allocation - - - - 104.1 -11.9 -4.2 4.1 General security off-allocation - - - - 86.6 -14.9 -3.7 5.6 Floodplain harvesting - - - - 0.003 -30.7 -10.5 72.3 Town water supplies - - - - 0.6 -0.4 -0.2 0.2 NSW Diversions Sub-total - - - - 191.3 -13.2 -4.0 4.7 Total Diversions - - - - 414.3 -15.13 -4.8 5.7 Losses River Losses 1191.7 -20.5 -8.9 12.7 1038.1 -27.8 -10.1 17.6 Evaporation from storages 20.7 -1.3 -0.2 2.7 50.3 -6.3 0.8 6.8 Net loss to groundwater -8.7 - - - -8.7 - - - Total Losses 1203.7 -20.3 -8.8 12.6 1079.7 -27.0 -9.7 17.3 Outflows EOS in Barwon @ Mungindi 539.5 -20.6 -8.5 10.7 317.0 -30.8 -11.9 18.1 EOS in Boomi @ Neewora 215.1 -19.3 -6.9 11.9 173.4 -35.6 -8.3 23.5 EOS in Little Weir @ Confluence 42.8 -27.7 -11.7 16.2 22.3 -47.6 -18.1 29.8 Total Outflows to Barwon-Darling 797.4 -20.6 -8.2 11.3 512.6 -33.2 -10.9 20.4 Unattributed Flux (GL) Total Unattributed Flux (GL) 1.10 - - - 1.43 - - -

4.7.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Gwydir system are summarised in Table 7. The Gwydir system has a good network of gauges on the contributing tributaries and as a consequence, 76% of the river system inflows are based on gauged data and only 24% are estimated using models. The total inflows in the Gwydir system are 996 GL/y and are estimated to decrease by 24% and9% under the 2030 Dry and Median climate scenarios, and to increase by 24% under the Wet climate change scenarios. Under Without Development Conditions, 43% of total inflows reaches the Barwon-Darling system> This has decreased to 17% under Baseline Conditions, with 32% of inflows being diverted.

The impact of climate change is likely to be different for different water users in the system under current water sharing arrangements. The impact on consumptive users and end of system flows are analysed and presented in Appendix 1. Under historical climate, diversions are 32% of system inflows. This proportion may increase to 35% or decrease to 29% for 2030 Dry and 2030 Wet climate scenarios, while for the Median climate change scenario, it is likely to remain at current level. The proportion of inflows that flows into Barwon-Darling is currently 17%, which could vary between 17% and 18% for the various climate scenarios.

4.8 NAMOI

4.8.1 MODEL DESCRIPTION

The Namoi region is in situated in north-eastern New South Wales. It covers 3.8 percent of the total area of the Murray-Darling Basin and has 4.5 percent of the total population of the basin (CSIRO, 2007b).

For the regulated parts of the Namoi and Peel catchments, two separate daily time step IQQM models have been set up by NSW’s Office of Water (NOW, DECCW). The Peel model covers sub-catchments of the Peel River from headwater inflows into the Dungowan Dam to its confluence with the Namoi River downstream of the Keepit Dam. The two models are linked together in the MDBA’s IRSMF modeling framework. The Namoi model covers the subcatchments of the Manilla River from its headwater inflows into Split Rock Dam, the Mooki River from Breeza gauge (419027) and the Namoi River from North Cuerindi gauge (419005) to lower flood plains of Namoi valley covered by Pian Creek and Namoi River and their anabranches. The Namoi River meets the Barwon River near Walgett Gauge (419057). Two simulated flows are taken as inflows into the Barwon-Darling model, i.e. at the Waminda gauge (419049) in the Pian Creek and the Goangra Gauge (419026) in the Namoi River.

TABLE 7 WATER BALANCES FOR THE GWYDIR SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage - - - - -7.4 3.8 0.6 -3.3 Inflows Directly gauged 755.6 -21.5 -10.5 25.1 755.6 -21.5 -10.5 25.1 Indirectly gauged 240.5 -31.8 -5.6 21.9 240.5 -31.8 -5.6 21.9 Total inflows 996.1 -24.0 -9.3 24.3 996.1 -24.0 -9.3 24.3 Diversions High security - - - - 9.5 6.7 3.28 0.9 General security on-allocation - - - - 198.5 -18.3 -12.0 15.0 General security off-allocation - - - - 86.5 -16.2 -7.0 13.5 Floodplain harvesting - - - - 17.7 -22.5 -5.7 18.2 Town water supply, Stock and Domestic - - - - 3.8 0.0 0.0 0.0 Total Diversions - - - - 316.0 -17.0 -9.6 14.2 Losses Net evaporation from Storage - - - - 23.3 -16.2 -8.8 12.7 River Losses 520.1 -23.6 -9.5 24.9 370.1 -25.7 -9.3 27.0 Effluent losses 1605.7 -23.3 -10.3 25.6 1289.2 -24.8 -10.5 30.3 Effluent returns -1457.6 -22.9 -10.2 25.2 -1168.1 -23.9 -10.4 29.0 Total Losses 668.2 -24.4 -9.8 25.8 514.4 -27.1 -9.6 30.2 Outflows Gil Gil Creek 129.0 -24.5 -8.2 20.8 79.3 -26.0 -6.9 20.4 Gwydir River at Collymongle 20.6 -27.8 -12.3 30.3 4.9 -34.0 -13.7 45.4 Mehi River at Collarenebri 279.9 -18.3 -8.2 20.7 89.0 -26.3 -7.3 26.4 Total Outflows to Barwon-Darling 429.5 -20.6 -8.4 21.2 173.2 -26.4 -7.3 24.2 Unattributed Flux (GL) Total Unattributed Flux (GL) -101.6 - - - -0.1 - - -

The development of the Namoi and Peel Cap models is described in detail in DIPNR (2004d) and DNR (2006c). These models were reviewed as part of the Cap Auditing and are accredited for Cap implementation (Bewsher, 2006a and 2009). There is no separate documentation of the Water Sharing version of the model, but environmental flow rules and water sharing arrangements in the model correspond to the Namoi Water Sharing Plan (DIPNR, 2004e) and the Peel River Water Sharing Plan (DECCW, 2010). The Water Sharing version of the Peel model has been updated by NSW’s Office of Water (NOW, DECCW), by recalibration of river losses, recalculation of the Dungowan Dam inflows and the inclusion of restrictions for Tamworth demands. The Namoi model has not been updated since 2003 and calibration for inflows and losses needs reviewing. The model does not include water buybacks by the Commonwealth and NSW governments since start of the Water Sharing Plan.

4.8.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Namoi and Peel system are summarised in Table 8. The system has a limited number of gauges on the contributing tributaries and as a consequence only 38% of the river system inflows are based on gauged data and 62% are estimated using models. The total inflows are 1883 GL/y and are expected to decrease under the 2030 Dry and Median climate scenarios by 20% and 6% and to increase under the Wet climate scenario inflows by 31%. Under Without Development Conditions, the proportion of total inflows that reaches the Barwon-Darling system is 44%. This has decreased to 35% under Baseline Conditions, with 14% of inflows being diverted.

The impact of climate change is likely to be different for different water users in the system under current water sharing arrangements. The impact on consumptive users and end of system flows are analysed and presented in Appendix 1. Under historical climate, diversions are 14% of system inflows. This proportion is likely to increase to 16% and 15% under the 2030 Dry and Median climate scenarios, while it may decrease to 11% under the 2030 Wet climate scenarios. On the other hand, the current proportion of inflows that flows into the Barwon-Darling (31%) is likely to decrease to 29% under the Dry climate scenario. It may remain at 31% under the Median scenario and increase to 33% under the Wet climate scenario.

TABLE 8 WATER BALANCES FOR THE NAMOI AND PEEL SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 586 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage - - - - -4.6 5.8 0.0 -9.4 Inflows Directly gauged 723.9 -20.1 -6.4 31.1 723.9 -20.1 -6.4 31.1 Indirectly gauged 1151.8 -20.5 -6.0 31.1 1151.8 -20.5 -6.0 31.1 Groundwater gain 7.5 -8.8 -2.8 8.2 9.1 -7.3 -2.2 6.8 Total inflows 1883.1 -20.3 -6.1 31.0 1884.8 -20.3 -6.1 31.0 Diversions General security on-allocation - - - - 200.8 -7.2 -1.7 5.8 General security off-allocation - - - - 40.4 -6.9 1.4 8.8 Floodplain harvesting - - - - 13.8 -9.7 1.3 17.4 Fixed demand (incl. TWS, S&D) - - - - 10.5 3.5 2.7 2.3 Total Diversions - - - - 265.5 -6.8 -0.9 6.7 Losses River groundwater loss 0.9 -32.9 -8.6 36.9 6.7 -4.9 -11.0 5.5 Storage evaporation losses 0.8 -9.3 -0.3 14.7 51.5 -3.4 1.7 9.4 River evaporation losses 17.8 0.0 0.0 0.0 18.2 0.0 0.0 0.0 River losses 1124.5 -19.8 -6.4 30.3 973.0 -21.8 -7.2 33.8 Effluent losses 209.5 -33.9 -6.5 53.6 322.2 -24.7 -4.9 38.8 Effluent return flows -209.5 -33.9 -6.5 53.6 -320.6 -25.4 -5.2 39.3 Irrigation drainage returns flows - - - - 8.2 -17.6 -7.7 21.5 Total Losses 1144.1 -19.5 -6.3 29.8 1042.8 -20.2 -6.5 31.8 Outflows End of System Outflows to Barwon-Darling Model 828.3 -21.4 -5.9 32.6 652.6 -25.7 -7.5 39.6 Total Modelled outflows 739.8 -21.6 -6.0 32.8 584.8 -26.0 -7.7 39.9 Unattributed Flux (GL) Total unattributed flux of end of model (GL) -0.7 - - - -3.6 - - -

4.9 MACQUARIE-CASTLEREAGH AND BOGAN RIVERS

4.9.1 MODEL DESCRIPTION

The Macquarie-Castlereagh and Bogan region is located in central-west NSW, covers 6.9 percent of the area of the MDB and has 9% of the total population of the basin (CSIRO, 2008h). The region comprises the Castlereagh, Macquarie and Bogan River basins. For regulated parts of the Macquarie River and for unregulated parts of the Castlereagh River, a daily time step IQQM model has been developed by the NSW’s Office of Water (NOW, DECCW). The Castlereagh system is modelled from inflows at Mendooran gauge (420004) in the Castlereagh River to its confluence with the Macquarie River. The Macquarie River is modelled from the headwater inflows into the Windamere Dam on the Cudgegong River and into the Ben Chifley Dam on the Macquarie River. The Macquarie outflows are inflows into the the Barwon River. In the IRSMF modeling framework, flows at five gauging stations from the Macquarie-Castlereagh model are used as inflows to the Barwon-Darling Model, i.e. Coonamble gauge in the Castlereagh River (420005), Marthaguy Creek at the Carinda gauge (421011), Macquarie River at the Carinda gauge (421012), Bogan River at the Gongolgon gauge (421023) and Marra Creek at the Billybingbone Bridge gauge (421107).

The development of the Macquarie River Cap model is described in detail in DNR (2006b). This model was reviewed as part of the Cap Auditing and is accredited for Cap implementation (Bewsher, 2007). There is no separate documentation of the Water Sharing version of the model, but environmental flow rules and water sharing arrangements in the model correspond to the Water Sharing Plans for the Macquarie and Cudegong Rivers (DIPNR, 2004b) and Castlereagh River (DIPNR, 2004c). The Water Sharing Plan versions of the models for Macquarie, Bogan, Marra, Marthaguy and Castlereagh were linked for the MDBSY project and this linked version of the model has been used for the Basin Plan modelling. The model does not include water buybacks by Commonwealth and NSW government since the start of the Water Sharing Plan.

4.9.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Macquarie- Castlereagh and Bogan system are summarised in Table 9. The system has a limited number of gauges on the contributing tributaries and as a consequence only 39% of the river system inflows are based on gauged data and 61% are estimated using models. The total inflows in the Macquarie-Castlereagh and Bogan system are 2859 GL/y and are estimated to change between a decrease of 21% and an increase of 24% under the Dry 2030 and Wet 2030 climate change scenarios, with a decrease of 8% under 2030 Median climate change scenario. The proportion of inflows that reaches the Barwon-Darling system under Without

Development Conditions is 27%. This has decreased to 22% under Baseline Conditions, with 14% of total inflow being diverted.

The impact of climate change is likely to be different for different water users in the system under current water sharing arrangements. The impact on consumptive users and end of system flows are analysed and presented in Appendix 1. Under historical climate, diversions are 14% of system inflows. This proportion is expected to increase to 16% and 15% under the Dry and Median climate scenarios, while it may decrease to 13% under the Wet climate scenario. On the other hand, the proportion of inflows that flows into Barwon-Darling system could vary between 20% and 24%, as estimated for the Dry and Wet climate scenarios respectively, and is likely to remain at the current percentage of 22% under the Median 2030 climate scenario.

4.10 BARWON-DARLING

4.10.1 MODEL DESCRIPTION

Barwon-Darling region is located in north-western NSW and covers 13 percent of MDB. The region has 2.5% of the basin’s population. The region contains the Talyawalka wetland system, which is a nationally important wetland, which is located between Wilcannia and Menindee on the Darling Riverine Plains (CSIRO, 2008a). For development of management policies and for general regulation of flows , a daily time step IQQM model was developed by the NSW’s Office of Water (NOW, DECCW). The model receives tributary inflows from the Gwydir, Namoi and Border-Rivers models in the reach of the Barwon River between the Mungindi and Walgett gauges, and from the Warrego, Condamine–Balonne and Macquarie- Castlereagh models in the reach between the Walgett and Louth gauges. The lower end of model covers wetlands, lakes and billabongs of the Talyawalka wetland system.

The Barwon-Darling is an unregulated system and in-stream minimum flows are ensured by specifying various flow thresholds for different irrigators with different licence classes. There are three irrigation license classes, i.e. Class A, B and C. The model used for Basin Plan development is at 2007/08 level of irrigation development and incorporates the Cap accounting rules of July 2007 (i.e. reduced entitlements and continuous carryover). There are issues with underestimation of inflows from the tributary models during some of the major floods. Therefore, estimates of additional flows, which may bypass the most downstream gauges of the tributary catchments, are included in the Barwon Darling model. The development of this model is described in detail in DNR (DNR, 2006a).

TABLE 9 WATER BALANCES FOR THE MACQUARIE-CASTLEREAGH AND BOGAN RIVER SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage - - - - -4.3 8.6 -0.1 -12.1 Inflows Directly gauged 1104.7 -21.8 -7.6 22.4 1104.7 -21.8 -7.6 22.4 Indirectly gauged 1754.4 -21.2 -8.6 24.4 1523.3 -19.6 -7.8 23.7 Total inflows 2859.1 -21.4 -8.2 23.6 2628.0 -20.5 -7.7 23.1 Diversions General security on-allocation - - - - 317.9 -11.6 -3.9 10.8 General security off-allocation - - - - 29.4 -10.8 -4.3 8.2 High Security - - - - 5.1 8.1 3.8 -2.0 Town water supply - - - - 27.9 -0.6 -0.2 0.2 Total Diversions - - - - 380.3 -10.5 -3.5 9.6 Losses On Farm Evaporation - - - - 5.0 -28.3 -12.6 15.1 River Losses 1576.8 -21.6 -8.5 23.4 1280.9 -21.0 -8.0 23.0 Net evaporation from storages - - - - 54.0 -2.8 1.3 6.7 Return flows 928.2 -21.3 -9.8 21.6 688.3 -23.7 -11.1 26.3 Macquarie Marshes evaporation 328.0 -12.7 -4.3 11.4 228.8 -20.8 -8.3 18.9 River evaporation 16.5 - - - 16.7 - - - Effluent losses 939.3 -21.4 -9.8 21.6 693.0 -23.7 -11.2 26.4 Total Losses 1932.4 -20.0 -7.8 21.2 1585.1 -20.1 -7.6 21.6 Outflows End of System Outflows to Barwon-Darling Model 760.0 -24.3 -8.5 29.5 576.9 -26.6 -9.4 34.6 Total Modelled outflows 926.7 -24.5 -9.3 28.6 667.3 -26.9 -10.3 34.0 Unattributed Flux (GL) Total Unattributed Flux (GL) 0.0 - - - -0.3 - - -

4.10.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Barwon- Darling system are summarised in Table 10. The Barwon-Darling system gets contributions from various tributaries, which have a gauging station near their confluence with the Barwon-Darling system. However, during flood events significant volumes of water can bypass these gauges and are then only measured at the gauging stations on the Barwon- Darling system. The volume of water that bypasses these tributary gauges can comprise a significant proportion of total Barwon-Darling inflows. This has been accounted for in the water balance as local inflows to the Barwon-Darling system. The total inflows in the Barwon-Darling system are estimated to be 4689 GL/y (under Without Development conditions) and are expected to change between a decrease of 23% and an increase of 25% under the Dry 2030 and wet 2030 climate change scenarios, with a decrease of 8% under 2030 Median climate change scenario. Under Without Development Conditions, 70% of total inflows reaches the Menindee Lakes. Under Baseline Conditions the inflows have decreased to 37% of Without Development inflows, which is 62% of Baseline inflows. Barwon-Darling Baseline inflows are affected by developments in all upstream river valleys, therefore variations in end of system flows are due to the combined effect of upstream valley developments and developments in the Barwon-Darling system itself.

The impacts of climate change on consumptive users and end of system flows are presented in Appendix 1. Under historical climate, diversions are 7% of system inflows. This proportion is expected to change to 10%, 8% and 5% under the Dry, Median and Wet 2030 climate change scenarios. The end of system flows into Menindee Lakes are expected to decrease under the Dry and Median climate scenarios, to respectively 33% and 36% of Without Development inflows (which corresponds to 61% and 62% of baseline inflows). For the Wet climate scenario, outflows are expected to increase to 39% of Without Development inflows (i.e. 62% of Baseline inflows).

4.11 LACHLAN

4.11.1 MODEL DESCRIPTION

The Lachlan region is situated in central western New South Wales. It covers 8 percent of the total area of the Murray-Darling Basin and has 4.7 percent of the population of the basin (CSIRO, 2008f).

TABLE 10 WATER BALANCES FOR THE BARWON-DARLING SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage ------Inflows Warrego 69.4 -21.7 -7.7 32.6 58.2 -24.0 -8.5 36.9 Condamine-Balonne 569.4 -20.2 -8.2 10.2 241.8 -28.5 -12.4 15.9 Moonie 96.3 -24.7 -11.8 18.9 71.4 -28.1 -13.6 22.7 Border Rivers 797.4 -20.6 -8.2 11.3 512.6 -33.2 -10.9 20.4 Gwydir 429.5 -20.6 -8.4 21.2 173.2 -26.4 -7.3 24.2 Namoi 828.3 -21.4 -5.9 32.6 652.6 -25.7 -7.5 39.6 Macquarie-Castlereagh 760.0 -24.3 -8.5 29.5 576.8 -26.6 -9.4 34.6 Local Barwon-Darling inflows 1138.4 -28.0 -10.0 36.5 481.9 -36.4 -9.9 53.8 Total Inflows 4688.7 -23.2 -8.4 25.4 2768.5 -29.5 -9.5 34.0 Diversions Metered Irrigation Class A - - - - 0.2 15.1 4.0 -8.1 Class B - - - - 127.0 2.1 2.0 0.0 Class C - - - - 52.1 -2.9 -0.5 0.1 Sub-total - - - - 179.4 0.7 1.3 0.0 Small Irrigators Class A - - - - 1.3 1.2 2.6 3.8 Class B - - - - 5.3 1.4 2.8 2.8 Sub-total - - - - 6.6 1.4 2.8 3.0 Flood plain harvesting - - - - 11.5 -11.9 -0.1 21.9 Total Diversions - - - - 197.4 0.0 1.2 1.4 Losses Evaporation losses from storages Warrego 32.3 -6.0 -4.0 7.2 28.2 -10.5 -6.2 11.8 Floodplain lakes 86.4 -22.4 -6.2 31.9 50.0 -34.3 -6.7 33.6 River evaporation 49.5 0.0 0.0 0.0 48.5 0.0 0.0 0.0 Sub-total storage losses 168.2 -12.6 -4.0 17.8 126.7 -15.9 -4.0 15.9

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) River Losses Reach losses 1160.9 -30.0 -10.1 36.0 677.8 -36.3 -11.8 49.2 Effluent losses 85.8 -30.9 -9.8 35.9 43.3 -42.8 -12.0 53.5 Sub-total river losses 1246.7 -30.1 -10.1 36.0 721.1 -36.7 -11.8 49.5 Total Losses 1414.9 -28.0 -9.3 33.9 847.9 -33.6 -10.6 44.5 Outflows Menindee Lakes EOS flow 3272.5 -21.2 -8.0 21.7 1721.2 -31.0 -10.3 32.5 Unattributed Flux (GL) Total Unattributed Flux (GL) 1.3 - - - 2.0 - - -

The Lachlan is modelled with a daily timestep IQQM model (Hameed and Podger, 2000). The Lachlan River is modeled from its headwater inflows into Wyangala Dam and Belulula River inflows to Carcoar Dam. The river breaks out into Willandra Creek and flows to Moomanyah Lake. The model ends at the Great Cumbung Swamp and has no contribution to any of the downstream systems. The model includes key water regulation storages (i.e. Wyangala Dam, Carcoar Dam, Lake Cargelligo, Brewster Weir and Lake Brewester).

The development of the Lachlan Cap model is described in DLWC (2002). The model has been reviewed as part of the Cap Auditing and has been accredited for Cap implementation (Bewsher, 2002b). There is no separate documentation of the Water Sharing version of the model, but environmental flow, irrigation demands and environmental flow rules in the model correspond to the Lachlan Water Sharing Plan (DIPNR, 2006e). The model does not include water buybacks by the Commonwealth and NSW governments since start of the Water Sharing Plan.

4.11.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Lachlan system are summarised in Table 11. The Lachlan system has good network of gauges on the contributing tributaries and as a consequence 70% of the river system inflows are based on gauged data and 30% are estimated using models. The total inflows in the Lachlan system are 1424 GL/y and are estimated to change decrease under the Dry and Median 2030 climate change scenarios, by 28% and 12% respectively. Under the Wet climate change scenario, inflows are expected to increase by 8%. The Lachlan is an isolated system; most of the time water ends in wetlands and billabongs with no contribution to Barwon-Darling or Murray River System.

The impacts of climate change on consumptive users and end of system flows are presented in Appendix 1. Under historical climate, diversions are 20% of system inflows. Under climate change, this proportion may change from an increase to 23% or a decrease to 19% for 2030 Dry and 2030 Wet climate scenarios, with an expected increase of 1% to 21% of inflows, under the Median climate change scenario.

TABLE 11 WATER BALANCES FOR THE LACHLAN SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage - - - - -9.1 1.0 0.6 -1.0 Inflows Directly gauged 991.8 -27.6 -12.1 5.8 991.8 -27.6 -12.1 5.8 Indirectly gauged 432.4 -29.8 -12.0 11.9 432.4 -29.8 -12.0 11.9 Total inflows 1424.3 -28.3 -12.1 7.7 1424.3 -28.3 -12.1 7.7 Diversions High security - - - - 9.7 14.6 4.8 2.3 General security - - - - 258.5 -20.8 -7.4 4.0 Town water supply - - - - 10.0 -1.0 -0.3 0.1 Stock and Domestic - - - - 8.9 -0.6 -0.2 0.1 Total Diversions - - - - 286.7 -18.3 -6.5 3.7 Losses Wetland replenishment - - - - 26.2 -2.9 -1.0 1.0 Environmental contingency flow - - - - 5.0 -45.9 -15.8 10.5 River groundwater loss - - - - 17.4 -0.8 -0.3 0.1 Evaporation from public storages - - - - 67.7 6.2 2.8 4.1 Evaporation from natural water bodies 170.3 -12.8 -3.5 7.9 84.0 -16.9 -4.3 8.7 River loss and effluent loss 1254.0 -30.4 -13.2 7.7 946.5 -35.6 -15.9 9.3 Total Losses 1424.3 -28.3 -12.1 7.7 1146.8 -30.6 -13.4 8.6 Outflows End of System Outflows ------Unattributed Flux (GL) Total Unattributed Flux (GL) -0.02 - - - -0.06 - - -

4.12 MURRUMBIDGEE

4.12.1 MODEL DESCRIPTION

The Murrumbidgee region is located in southern NSW and covers 8.2% of the Murray Darling Basin (MDB). The region is home to 27% of the total population of the MDB (CSIRO, 2008l). It includes the nationally significant Mid-Murrumbidgee wetlands and Low Murrumbidgee floodplain, as well as the extensive Murrumbidgee and Colleambally Irrigation Areas.

The Murrumbidgee model is comprised of three main models linked together as described below. A separate document has been prepared that outlines the linkages in more detail (MDBA, 2010a).

 The Upper Murrumbidgee model (UBID) begins at Tantangara Storage and includes the ACT, with a final outflow acting as inflow to Burrinjuck Dam. The ACT itself is represented by the outflows from Googong and Cotter Dams, as provided to MDBA by ACTEW.  The Snowy Scheme (SNAT and SNOW): For Without Development Conditions, flows into Blowering and Tantangara are represented without any Snowy Scheme contribution, using the Snowy model SNAT. To determine the net effect of the snowy scheme on Murrumbidgee flows, a further Snowy model (SNOW) represents inflows to Blowering Dam from the Snowy Hydro Scheme, and also minor flows to upper Murrumbidgee through Tantangara. SNOW is the model used for both Baseline and Basin Plan scenarios.  The Murrumbidgee model (BIDG) commences at Burrinjuck and Blowering Dams and ends at the three main EOS points, i.e. Murrumbidgee River at Balranald, Billabong Creek at Darlot and Forest Creek downstream of Warriston Weir. The Murrumbidgee River and Billabong Creek flow into the River Murray, whereas Forest Creek ends in a floodplain. Storages modelled for the Murrumbidgee system are: Burrinjuck Dam, Blowering Dam, Redbank Weir, Maude Weir, Berembed Weir, Gogelderie Weir and Hay Weir. The model also includes Barren Box Swamp, Tombullen Storage and Warraridge Storage.

The Cap version of the Murrumbidgee model (BIDG) is described in DIPNR (2004f). There is no further documentation on the version of the model used here, which corresponds to the Water Sharing Plan (DIPNR, 2004f; DWE, 2009). The Water Sharing Plan model version does not include Water Recovery for TLM, River Bank or Snowy Scheme Water for Rivers or any Commonwealth Environmental water holders.

Several changes were subsequently carried out to the Murrumbidgee model as compared to the version used for MDBSY. The changes are:

 The Baseline Murrumbidgee model now includes the Yanco-Billabong system (which was a separate model) and includes linked flows from the Upper Murrumbidgee and Snowy Scheme.  The model has been extended to include the Jounama catchment upstream of Blowering Dam.  The Snowy model is a new model based on that used in SY, but updated and revised by Snowy Hydro Limited and CSIRO.  The Without-Development model is also a new model, developed by NSW’s Office of Water, and is based on the Baseline model to keep node numbers and locations identical.  Water recovery for TLM was added to the Baseline Conditions model. For Basin Plan modelling, Water Recovery for TLM and Water for Rivers is accounted for by correcting diversions and inflows after the model is run.  The Balranald end-of-system flow demand was updated to include the WSP 08-09 minimum flow rule.  Flows representing Inter-Valley-Trade with the Murray system were updated based on the most recent information produced by the Murray model.

4.12.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Murrumbidgee system are summarised in Table 12. The system has a reasonable number of gauges on the contributing tributaries, and as a consequence 85% of the river system inflows are based on gauged data, and only 15% are estimated using models. The total inflows in the Murrumbidgee system excluding Snowy (for Without Development Conditions) are 4236 GL/y and are estimated to change between a decrease of 24% and an increase of 10% under the Dry and Wet 2030 climate change scenarios, with a decrease of 9% under the Median climate change scenario. For Baseline Conditions the total inflows are higher due to the transfer from the Snowy River (included in the directly gauged inflows) and Inter-Valley Trade. Total inflows under Baseline Conditions are 4742 GL/y, and are expected to change by -23% (2030 Dry), +10% (2030 Wet) and -8% (2030 Median) under climate change.

For the Murrumbidgee, 68% of its total inflows reach the Murray system under Without Development Conditions. Under Baseline Conditions, this has decreased to 34% of total baseline inflows, with diversions being 44% of baseline inflows.

TABLE 12 WATER BALANCES FOR THE MURRUMBIDGEE SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage - - - - -16.9 7.6 3.8 -7.2 Inflows Directly gauged 3610.4 -22.2 -8.0 9.5 4073.7 -21.9 -7.5 9.3 Indirectly gauged 625.8 -34.1 -12.0 13.0 625.8 -34.1 -12.0 12.9 Transfer from Murray through Finlay’s Escape - - - - 42.1 0.0 0.0 0.0 Total inflows 4236.3 -24.0 -8.6 10.0 4741.6 -23.3 -8.0 9.7 Diversions Murrumbidgee irrigation area - - - - 987.9 -3.4 0.3 2.7 Colleambally irrigation area - - - - 464.5 -10.7 -1.8 4.1 Non irrigation area - - - - 492.0 -18.1 -4.8 5.4 Lowbidgee flood control irrigation - - - - 149.9 -24.7 -8.2 8.5 Town water supply NSW - - - - 12.9 -0.2 0.0 0.0 Total Diversions - - - - 2107.3 -9.9 -2.0 4.0 Losses Net evaporation from NSW storages - - - - 32.0 14.8 6.8 5.5 Lowbidgee evaporation total 310.6 -17.5 -5.6 10.8 215.5 -33.1 -11.1 13.5 River losses 960.2 -27.4 -10.4 12.5 822.1 -27.4 -9.9 12.5 Irrigation returns to Murrumbidgee & Yanco - - - - -122.4 -20.9 -4.2 7.2 Total Losses 1270.8 -25.0 -9.2 12.1 947.4 -28.1 -10.4 13.1 Outflows Billabong Creek at Darlot (to Murray, via Edward R.) 123.5 -44.1 -19.3 17.3 321.7 -30.3 -11.3 10.4 Murrumbidgee River at Balranald (to Murray) 2724.2 -23.6 -8.2 8.9 1223.1 -42.9 -16.2 17.2 Forest Creek (to floodplain) 29.9 -40.7 -18.8 13.1 56.9 -32.2 -12.8 10.3 Total Outflows 2877.5 -24.7 -8.8 9.3 1601.7 -37.2 -12.2 18.5 Unattributed Flux (GL) Total Unattributed Flux (GL) 88.0 - - - 102.2 - - -

The impacts of climate change on consumptive users and end of system flows are presented in Appendix 1. Under a historical climate and Baseline Conditions, diversions are 44% of system inflows. This proportion is expected to increase under all climate change scenarios to 52% for the Dry, and 47% for the Median and Wet 2030 climate scenarios. On the other hand, the proportion of inflows that flows into the Murray system is expected to decrease under all climate scenarios, from the current 34% to 28%, 32% and 31% for the Dry, Median and Wet scenarios, respectively.

4.13 OVENS

4.13.1 MODEL DESCRIPTION

The Ovens region is in north eastern Victoria. It covers and 0.7 percent of the total area of the Murray-Darling Basin and has 2.3 percent of the total population in the basin (CSIRO, 200). The Ovens system is modelled with a weekly REALM model (Perera and James, 2003) that covers the entire Ovens River from the northern slopes of Mount Hotham and Mount Buffalo through the Ovens valley, passing numerous regional towns. The system is modelled to the confluence with the Murray River upstream of Yarrawonga Weir. The most downstream gauge on the Ovens River is at Peechelba (403241). The Ovens model has been developed in 1995 and there have been various reviews and updates since then. The most recent review and recalibration is described in SKM (2008). The Ovens model was received from the Victorian Department of Sustainability and Environment (DSE). The model inputs were last updated to December 2008 by SKM (2009b). The model represents the current level of development and water sharing rules as of 2009. The water sharing rules are documented in the relevant bulk entitlements for the Ovens River (DSE, 2010).

4.13.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Ovens system are summarised in Table 13. As mentioned above, the model has been updated to December 2008 and does not cover the whole Basin Plan Baseline period, up to June 2009. Hence, the water balances provided present annual average figures for the period from July 1895 to December 2008.

The inflows to the Ovens model are determined using a range of different methods, including gauged tributary flows that may be factored to account for the ungauged part of the tributary catchment downstream of the gauge, as well as water balance methods and rainfall-runoff modelling (SKM, 2009). The Ovens catchment has a relatively high number of gauges and 75% of the inflows have been identified as directly gauged. The total inflows in the Ovens system are expected to decrease by 31% and 13% for the Dry and Median climate

44 change scenarios. Under the Wet climate change scenario, Ovens inflows may increase by 1%. For the Ovens system, 99% of inflows reaches the Murray system under Without Development Conditions, as only 1% of inflows is lost. Under Baseline Conditions, still 97% of inflows flows into the Murray, which highlights a relatively low level of development in the catchment; only 2% of inflows is diverted under the current conditions and historical climate.

Under current conditions, the diversions may increase to 3% of total inflows under the Dry and Median 2030 climate scenarios, while end of system flows are expected to decrease to 94% and 96% under these respective scenarios. For the Wet climate change scenario the proportions of inflows being diverted and reaching the end of system are estimated to stay the same as under current conditions (Appendix 1).

TABLE 13 WATER BALANCES FOR THE OVENS SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS (FOR PERIOD FROM JULY 1895 TO DECEMBER 2008).

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage 0.0 - - - 0.1 0.0 0.0 0.0 Inflows Directly gauged 1318.8 -31.2 -12.5 0.8 1318.8 -31.2 -12.5 0.8 Indirectly gauged 434.0 -31.9 -12.5 0.9 456.5 -31.8 -12.5 0.9 Total inflows 1752.8 -31.3 -12.5 0.8 1775.4 -31.3 -12.5 0.8 Diversions Licensed private diversions - - - - 17.3 5.2 2.3 1.7 Urban diversions - - - - 7.0 1.4 1.4 0.0 Groundwater - - - - 1.1 0.0 0.0 0.0 Total Diversions - - - - 25.4 3.9 2.0 1.2 Losses Net Evaporation - - - - 1.5 -86.7 -120.0 -140.0 Farm dam impact - - - - 14.0 0.0 0.0 0.7 River Losses 17.6 23.3 5.1 -6.8 19.4 37.6 6.7 -11.9 Total Losses 17.6 23.3 5.1 -6.8 34.9 17.2 -1.4 -12.3 Outflows End of System flows (Peechelba) 1735.2 -31.9 -12.7 0.9 1715.0 -32.9 -12.9 1.0 Unattributed Flux (GL) Total Unattributed Flux (GL) 0.0 - - - 0.0 - - -

4.14 GOULBURN-BROKEN, CAMPASPE AND LODDON RIVERS

4.14.1 MODEL DESCRIPTION

The Goulburn-Broken, Campaspe and Loddon regions are situated in northern Victoria. The regions cover 4.8% of the area of the Murray Darling Basin (including the Avoca region) and have 16% of the basins population (CSIRO, 2008d; 2008b; 2008g).

The Goulburn-Broken, Campaspe and Loddon River systems are modelled together in the monthly REALM ‘Goulburn Simulation Model’ (GSM). These three rivers are modelled together, because they are hydrologically linked. The Broken River flows into the Goulburn River near Shepparton, and the Goulburn, Campaspe and Loddon rivers are all linked via the Waranga Western Channel (WWC), which transfers water from the Goulburn River to the Campaspe and Loddon River catchments. The Waranga Western Channel continues on from the Loddon River catchment through to the Wimmera region. The GSM includes outflows from Casey’s Weir to Broken Creek, but does not model Broken Creek. Due to the links between the three different river systems, changes in one part of the GSM can affect flows and reliability of supply in other GSM river systems.

The GSM REALM model was provided by the Victorian Department of Sustainability and Environment (DSE). The configuration of the GSM model is described in the Cap report (DSE, 2005). This model was audited and accredited for use for Annual Cap Auditing (Bewsher, 2006b). The last major model configuration is described in DSE (2007). The GSM model inputs were updated and cover the period of May 1891 to June 2009 (SKM, 2009a). The Baseline model being used represents the current level of development and water sharing rules as of 2009, but with some exceptions, where infrastructure or water sharing rules are in the process of being changed. The water sharing rules are documented in the relevant bulk entitlements for the Goulburn, Broken, Campaspe and Loddon Rivers (DSE, 2010).

Some key features of the model are:

 It includes Winton Swamp (27 GL capacity), which was previously the site of Lake Mokoan (365 GL capacity), which has been decommissioned;  It includes water recovery projects of Improved Measurement of Small Volume Supplies in Irrigation Districts - excluding Normanville and Woorinen (IMSVID) by Water for Rivers, Normanville pipeline, Strategic measurement, Shepparton Irrigation Area modernisation and reconfiguration works to the Snowy Environmental Water Reserve (15.3 GL/yr High Reliability Water Share, HRWS), the Living Murray (39.7 GL/yr HRWS and 20.8 GL/yr Low Reliability Water Share, LRWS) and the Goulburn Environmental Water Reserve (9.9 GL/yr HRWS and 19.9 GL/yr LRWS);

 It includes the unbundling of entitlements and the reallocation of 20% of sales water (141.2 GL/yr from the Goulburn River, 5.0 GL/yr from the Campaspe River) to the Living Murray low reliability water share and 2.0 GL/yr to the Loddon River low reliability water share;  It includes inter-valley trade (110.2 GL of permanent trade from the Goulburn system to the Murray system, 1.0 GL from the Campaspe system to the Murray system) and exchange rate trade of 1.2 GL/yr from the Campaspe system to the Murray system;  It excludes the 225 GL/yr of water savings and infrastructure changes under the Northern Victoria Irrigation Renewal Project (NVIRP). Part of NVIRP is the Sugarloaf Interconnector pipeline to Melbourne, which will deliver up to 75 GL/yr from the Goulburn River downstream of Lake Eildon to Melbourne and this is also excluded from the model;  It excludes the proposed decommissioning of irrigation supplies to the Campaspe Irrigation District (19.5 GL HRWS and 10.2 GL LRWS entitlement);  It excludes the connection of the town of Axedale to the Bendigo water supply system. The town is assumed to source its 0.1 GL/yr from the Campaspe River; and  It excludes the Goldfields superpipe, which supplies water to Ballarat (up to 18 GL/yr) and Bendigo (up to 20 GL/yr). The pipe runs from the Waranga Western Channel near Colbinabbin to Sandhurst Reservoir in the Bendigo urban system then to White Swan Reservoir in the upper reaches of the Barwon River basin in southern Victoria.

4.14.2 RESULTS AND DISCUSSION

Goulburn-Broken

The water balances for Without Development and Baseline Conditions for the Goulburn- Broken system are summarised in Table 14. Only 11% of inflows are indicated to be based on directly gauged data. However, this does not indicate that only 11% of the total catchment area has been gauged. The Victorian catchments have a large number of gauges that have been used to estimate inflows. The inflows to the various river reaches have been estimated using a various methods including ‘gauged and transposed flows’ (i.e. gauged tributary flows factored up to include an estimate of the ungauged part of the tributary catchment below the gauges) and water balance methods based on main stream gauges (SKM, 2009). The total inflows in the Goulburn-Broken system under historical climate are 3378 GL/y. These inflows are estimated to decrease by 32%, 13% and 3% under the Dry, Median and Wet 2030 climate change scenarios, respectively. For the Goulburn-Broken system it is estimated that 99.7% of its total inflows would reach the Murray system under Without Development Conditions, which has been decreased to 49% under Baseline Conditions. The GSM Predevelopment model does not include an estimate of river losses 48 along the Goulburn River; the river loss reported in the water balances for the predevelopment scenarios are only for the Broken system. The Baseline model only includes an estimate of additional river losses along the upper Goulburn that occur due to river operations. This may have been compensated in the Murray model by a higher loss estimate for the Yarrawonga and Torrumbarry river reach. The modelling of losses in the Goulburn and Murray models needs to be reviewed.

Under current conditions and historical climate, 47% of the total inflows is diverted. This proportion is expected to increases under all climate scenarios, with estimated diversions ranging from 56% for the dry scenario to 48% for the wet scenario. On the other hand, the proportion of inflows that will reach the Murray system will decrease under all climate scenarios, from 49% under current conditions to 39%, 45% and 48% under the dry, median and wet climate scenarios. This highlights that the reduction in inflows expected under climate change will affect end of system flows to a larger extent than the diversions (Appendix 1).

Campaspe

The water balances for Without Development and Baseline Conditions for the Campaspe system are summarised in Table 15. Only 1% of the river system inflows are based on directly gauged data and the rest of the 99% of inflows are estimated based on a range of different methods (SKM, 2009), including methods whereby gauged tributary flows are multiplied by factors to take into account ungauged parts of the tributary catchments and water balance methods. The total inflows in the Campaspe system are currently 290 GL/y and are estimated to decrease by 39%, 16% and 4% under the Dry, Median and wet 2030 climate change scenarios. For the Campaspe system, it is estimated that 97% of its total inflows reaches the Murray system under Without Development Conditions, which has been decreased to 53% under Baseline Conditions.

Under current conditions and historical climate, 39% of the total inflows is diverted. This proportion is expected to increases under all climate scenarios; to 56% for the dry climate scenario and to 42% for the median and wet climate scenarios. On the contrary, the proportion of inflows that will reach the Murray system will decrease under all climate scenarios, from 54% under current conditions to 33%, 49% and 50% under the dry, median and wet climate scenarios. As for the Goulburn-Broken system, this highlights that the reduction in inflows expected under climate change will affect end of system flows to a greater extent than the diversions (Appendix 1).

Loddon

The water balances for Without Development and Baseline Conditions for the Loddon system are summarised in Table 16. The inflows of the Loddon system are all indirectly gauged; they are estimated based on regressions with nearby tributary gauges and water balances with mainstream gauges (SKM, 2009). The total inflows in the Loddon system are

49 currently 255 GL/y and are estimated decrease by 45%, 15% and 9% under the Dry, Median and Wet 2030 climate change scenarios, respectively. For the Loddon system it is estimated that 94% of its total inflows reaches the Murray system under Without Development Conditions, which has decreased to 49% under Baseline Conditions.

Under historical climate, diversions comprise 37% of the total system inflows. This proportion is expected to increase under all climate change scenarios, to 48%, 40% and 39% for the Dry, Median and Wet 2030 climate scenarios, respectively. On the other hand, the proportion of inflows that reaches the Murray system would decrease from the current 49% to 31%, 45% and 47% under the Dry, Median and Wet climate scenarios. This reduction in end-of-system flows under the climate change scenarios is due to the increased consumptive use.

4.15 WIMMERA

4.15.1 MODEL DESCRIPTION

The Wimmera region located in western Victoria. It covers 3% of the total area of the MDB and has 2.5% of the MDB’s population (CSIRO, 2007e). The Wimmera model is a monthly REALM representation of the Wimmera River, as well as the Glenelg River to downstream of Rocklands Reservoir and the Avon-Richardson Rivers, where they interact with the Wimmera headworks system. The model has been provided by the Department of Sustainability and Environment. The Cap version of the model has been described in W&D, (2009). The model used by MDBA for basin plan modelling represents the current level of development and water sharing rules as of 2009, but with some exceptions where infrastructure or water sharing rules are in the process of being changed. The water sharing rules are documented in the relevant bulk entitlements for the Wimmera and Glenelg Rivers (DSE, 2010).

There is about 60 GL inter-basin transfers into the Wimmera system from the Glenelg River that runs south from Grampians Ranges.The model includes Stages 1 to 7 of the Northern Mallee pipeline and includes Supply Systems 1 to 6 (i.e. all supply systems) of the Wimmera- Mallee Pipeline. The model includes supply to the Horsham Irrigation District (28 GL/yr entitlement), which has since been proposed to decommission.

TABLE 14 WATER BALANCES FOR THE GOULBURN-BROKEN SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage -0.01 -35.6 -15.1 -10.5 -15.4 -35.9 -8.4 -1.5 Inflows Directly gauged 373.8 -35.7 -14.0 -2.2 373.8 -35.7 -14.0 -2.2 Indirectly gauged 3003.8 -31.2 -12.5 -2.5 3004.8 -31.2 -12.5 -2.5 Total inflows 3377.6 -31.7 -12.7 -2.5 3378.6 -31.7 -12.7 -2.5 Diversions Broken Diversions Licensed private diverters - - - - 10.7 6.9 3.2 4.4 Stock and domestic - - - - 2.3 2.7 1.0 0.4 Urban supply - - - - 0.1 -3.4 -0.6 -0.2 Broken Diversions sub-total - - - - 13.2 6.1 2.8 3.6 Goulburn Diversions Licensed private diverters - - - - 34.0 4.7 2.8 5.1 Irrigation districts through EGM - - - - 302.9 -23.5 -7.1 -0.5 Irrigation districts through WWC - - - - 1207.9 -18.9 -6.1 -0.7 Urban supply - - - - 18.9 0.5 0.2 0.1 Goulburn Diversions sub-total - - - - 1563.7 -19.1 -6.0 -0.5 Total Goulburn-Broken Diversions - - - - 1576.9 -18.8 -5.9 -0.5 Losses Irrigation drainage returns - - - - -28.1 -37.6 -15.0 -4.0 River losses 2.6 -42.5 -13.4 -2.4 167.7 -27.3 -10.4 -2.2 Net evaporation 7.0 -6.3 -0.2 2.0 31.0 31.1 19.0 14.7 Total Losses 9.7 -16.1 -3.8 0.8 170.5 -15.0 -4.3 1.2 Outflows End of system flow at McCoys Bridge (to Murray) 3368.0 -31.7 -12.7 -2.5 1645.7 -45.8 -19.9 -4.8 Total Modelled Outflows 3368.0 -31.7 -12.7 -2.5 1645.6 -45.8 -19.9 -4.8 Unattributed Flux (GL) Total Unattributed Flux (GL) 0.01 - - - 1.09 - - -

TABLE 15 WATER BALANCES FOR THE CAMPASPE SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

TABLE 16 WATER BALANCES FOR THE LODDON SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage 0.00 - - - -1.22 -6.0 -14.9 -24.5 Inflows Indirectly gauged 255.4 -45.0 -14.8 -8.8 255.4 -45.0 -14.8 -8.8 Total inflows 255.4 -45.0 -14.8 -8.8 255.4 -45.0 -14.8 -8.8 Diversions Licensed private diverters - - - - 13.9 -4.9 3.6 5.8 Irrigation districts - - - - 5.9 -8.8 -3.3 -3.8 Flow to Warranga Western Channel - - - - 70.9 -38.7 -12.4 -9.1 Stock and domestic - - - - 1.4 -11.7 -1.0 -0.8 Urban supply - - - - 1.3 31.3 -15.9 57.5 Environmental diversions (Boort wetlands) - - - - 2.1 -19.8 -3.9 0.2 Total Diversions - - - - 95.6 -30.1 -9.2 -5.3 Losses Net evaporation - - - - 13.1 -4.0 3.1 0.0 Channel losses 16.9 -9.4 -3.2 -4.2 21.9 -13.9 -3.3 -3.9 Total Losses 16.9 -9.4 -3.2 -4.2 35.0 -10.2 -0.9 -2.5 Outflows End of system flow at Appin South (to Murray) 144.7 -39.1 -13.7 -8.9 60.9 -50.3 -15.1 -4.6 To flood breakouts u/s from Appin South 93.7 -60.5 -18.6 -9.6 64.6 -79.9 -30.2 -21.8 Total Outflows 238.5 -47.5 -15.6 -9.2 125.6 -65.5 -22.9 -13.4 Unattributed Flux (GL) Total Unattributed Flux (GL) 0.00 - - - 0.08 - - -

There is 40.56 GL of environmental water entitlement in the model, which includes 32.2 GL/yr from the Northern Mallee Pipeline Stages 1 to 7 water savings and 8.3 GL/yr from the Wimmera-Mallee Pipeline Supply Systems Stages 1 to 6. The allocations to these entitlements are managed as a combined volume, which is shared between the Wimmera and Glenelg systems. The average annual regulated environmental release from these entitlements, as modelled with the Basin Plan Baseline model, is 14.7 GL/y for the Glenelg River and 22.0 GL/year for the Wimmera River.

The surface water of the Wimmera River is not connected to the River Murray and hence has no downstream impact on other reporting regions in the MDB.

4.15.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Wimmera system are summarised in Table 17. Only 6% of the total inflows in the Wimmera system are based on directly gauged data and the rest of 94% are indirectly gauged. The total inflows to the Wimmera system, under Without Development Conditions are 248 GL/y. However, under current conditions, inflows are higher due to the 60 GL/y transfer from the Glenelg River. The Baseline inflows are estimated to decrease by 44%, 14 and 3% under the Dry, Median and Wet 2030 climate change scenarios, respectively. From the Wimmera system there are no outflows into the Murray system and the system ends in terminal lakes, including Lake Hindmarsh, Lake Albacutya and a series of smaller lakes in the Mallee. These flows to lakes and wetlands have been included in the water balance under Losses.

Under historical climate, the diversions represent 24% of the total system inflows under Baseline Conditions. This proportion may increase to 29% and 25% under the Dry and Median climate scenarios and may remain at 24% under the Wet climate scenario (Appendix 1). On the other hand, under current conditions and historical climate, the flows to lakes and wetlands within the Wimmera system is estimated to be 8% of total inflows, which is expected to decrease to 7% under the Dry and Median 2030 climate change scenarios.

TABLE 17 WATER BALANCES FOR THE WIMMERA SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

4.16 MURRAY

4.16.1 MODEL DESCRIPTION

The Murray region straddles southern New South Wales, northern Victoria and south- eastern South Australia. It represents 19.5 percent of the total area of the Murray-Darling Basin and has of the basin’s population (CSIRO, 2008j).

The Murray and Lower Darling systems are modelled using a monthly simulation model called MSM and daily routing model, Bigmod. The modelling suite is also used for Cap purposes (MDBC 2007; Bewsher, 2008). The model commences with headwater inflows from the Murray River about 40 km south of Mt Kosciusko and Darling River inflows into Menindee Lakes. The model finishes at the barrages of lower lakes (MDBC, 2002a). More recently, a hydraulic model developed by Ian Webster (Webster, 2007) is included for hydrodynamic behaviours and salinity in Coorong. The model receives inflows from the Snowy Mountain Hydro Scheme (SMHS) via releases through the Murray 1 Power Station (WAMC, 2002). It also receives inflows from a number of tributaries including:

 Kiewa River at Bandiana,  Ovens River at Peechelba,  Goulburn River at McCoy’s Bridge,  Campaspe River at Rochester,  Loddon River at Appin South,  Billabong Creek at Darlot,  Murrumbidgee River at Balranald, and  Barwon-Darling as inflows to Menindee Lakes.

The model includes the four major storages: Dartmouth Dam on the Mitta Mitta River, Hume Dam on the Murray River, Menindee Lakes on the Lower Darling system and Lake Victoria (an off-river storage connected to the Murray River). The Menindee Lakes system is modelled as four major lakes: Wetherell, Pamamaroo, Menindee and Cawndilla. Also a number of weir pools and natural wetlands and floodplains are included in the model. A number of smaller weirs are not included as they do not impact on monthly operations (MDBC, 2007). Recently, as a part of The Living Murray (TLM) program, MSM has been extended from the SA border to Lower Lakes with three river reaches and two lake storages. Note that these new reaches do not have routing functionality unlike to the existing reaches. The model simulates:

 water accounts using the arrangements in the Murray-Darling Basin Agreement of Water Act (Commonwealth of Australia, 2007)  resources available to the states under the Agreement

 allocation by states to groups of water users  demand for water in the key regions throughout the system  transfers required between storages to ensure that the demands can be met  operation of various dams and structures including orders to meet forecast demands and pre-releases from each storage for flood mitigation

The environmental flow provisions included in the Baseline Conditions model are:

1. Additional dilution flows of 3,000 ML/day subject to Menindee Lakes storage (more than 1,650 GL in June and July, 1,500 GL in August and 1,300 GL in any other months) and combined storage of Hume and Dartmouth Dams being more than 2,000 GL 2. Darling anabranch environmental releases during period of off-allocation on the Lower Darling 3. Environmental water allocation of 150 GL for Barmah-Millewa Forest watering rules (MDBC 2006a, 2006b) 4. A 500 GL long term cap equivalent (LTCE) water recovery for The Living Murray (TLM) initiative (Table 18 ) and environmental water delivery of the recovered water 5. River Murray Increased Flow (Table 19)

TABLE 18 TLM WATER RECOVERY PROJECTS

Propo LTCE Entitlem Project Category of Entitlement nent (GL) ent (GL) MIL 17.8 100.0 NSW Murray Supplementary Water Pipe It 0.1 0.2 NSW Murray General Security Water 69.2 NSW Murray General Security Water 1.1 NSW Murray High Security Water Market Purchase Measure 102.5 0.5 Lower Darling High Security Water NSW 150.0 Lower Darling Supplementary Water 58.8 Murrumbidgee General Security Water Ricegrowers' On-farm water Efficiency 0.9 1.5 NSW Murray General Security Water Tandou Limited 24.0 100.0 Lower Darling Supplementary Water Darling Anabranch 46.1 47.8 Lower Darling General Security Water Poon Boon Lakes 8.5 - Modelled 98.8 Vic Murray Low Reliability Water Share Sales Unbundling 125.9 141.2 Goulburn Low Reliability Water Share 5.1 Campaspe Low Reliability Water Share 5.7 Vic Murray High Reliability Water Share Victorian Reconfiguration 22.8 VIC 19.2 Vic Trib High Reliability Water Share 20.5 Vic Trib High Reliability Water Share Shepparton Modernisation 30.16 15.8 Vic Trib Low Reliability Water Share Lake Mokoan decommissioning with 29.4 - Modelled Snowy HRWS 19 GL 18.9 SA Government Held water 12.3 SA 36.6 South Australia River Murray 4.3 Purchase from Willing Sellers 1.1 0.2 NSW Murray General Security Water AG Water Efficiency Tender 0.2 0.1 Lower Darling General Security Water 7.3 South Australia River Murray Living Murray Water Purchase 20.4 12.8 Vic Murray High Reliability Water Share MDBA 1.9 Vic Murray High Reliability Water Share Pilot Market Purchase 14.2 16.8 NSW Murray General Security Water

TABLE 19 SNOWY WATER RECOVERY AND ENTITLEMENT

Entitlement Valley License Comment (GL/yr) High Security 0.000 NSW Murray General Security 21.910 HRWS 37.200 VIC Murray LRWS 5.533 High Security 80.969 Returned through Snowy- Murrumbidgee General Security 33.54 Tumut HRWS 20.788 Added to Goulburn IVT Goulburn LRWR 17.930 account

4.16.2 RESULTS AND DISCUSSION

The water balances for Without Development and Baseline Conditions for the Murray and Lower Darling system are summarised in Table 20. The Murray and Lower Darling system is well gauged and only a small fraction (<2%) of its inflows are estimated inflows. The total inflows into the Murray and Lower Darling system under Without Development Conditions are 16,566 GL/y and are estimated to change from a decrease of 28% under the Dry climate change scenario to an increase of 6% under the Wet scenario, with a decrease of 10% under the Median climate change scenario. The total inflows under Baseline Conditions have been reduced due to developments in its contributing catchments and are 12,401 GL/y under historical climate. The climate change impact on baseline inflows is bigger than under Without Development Conditions and varies between a reduction of 33% under the Dry scenario and an increase of 7% under Wet scenario, with a reduction under the Median climate change scenario of 12%. Under Without Development Conditions 75% of the total Murray and Lower Darling inflows reach the sea through the Murray mouth. Under Baseline Conditions this has decreased to 41% of current inflows, which corresponds to only 31% of the Without Development inflows.

Under historical climate, the current diversions are 24% of the Without Development inflows (33% of Baseline inflows). This proportion is expected to increase to 28% and 27% of Without Development inflows under the Dry and Median climate change scenarios. Under the 2030 Wet climate scenarios, diversions are expected to remain at 24% of total Without Development inflows. The total end of system flows are expected to decrease under Dry and Median climate scenarios to 18 and 26% of Without Development inflows. Under the Wet climate change scenario the end of system flows may increase to 32% (Appendix 1).

TABLE 20 WATER BALANCES FOR THE MURRAY SYSTEM FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Storage Total change in storage -13.0 9.5 3.0 -8.7 -73.6 9.2 2.8 0.0 Inflows Darling (inflow to Menindee Lakes) 3272.5 -21.2 -8.0 21.7 1721.2 -31.0 -10.3 32.5 Murrumbidgee (Balranald) 2724.2 -23.6 -8.2 8.9 1271.4 -42.0 -15.8 16.6 Murrumbidgee (Darlot) 123.5 -44.1 -19.3 17.3 321.7 -30.3 -11.3 10.4 SMHS releases 616.9 -19.3 -5.4 5.8 1143.9 -15.9 -4.5 3.8 Ovens at Peechelba 1728.2 -31.9 -12.7 0.9 1708.0 -32.9 -12.9 1.1 Goulburn at McCoy’s Bridge 3368.0 -31.7 -12.7 -2.5 1660.0 -46.1 -19.8 -4.8 Campaspe at Rochester 280.8 -38.6 -16.1 -3.5 150.6 -63.8 -24.6 -9.6 Loddon at Appin South 144.7 -39.1 -13.7 -8.9 60.9 -50.3 -15.1 -4.6 Directly gauged Murray subcatchments 4047.1 -30.3 -10.2 2.8 4035.9 -30.4 -10.2 2.8 Indirectly gauged Murray subcatchments 260.2 -32.2 -14.5 6.6 327.6 -26.3 -11.7 5.2 Total inflows 16566.0 -27.8 -10.3 6.3 12401.1 -33.2 -12.2 7.3 Diversions NSW Murray diversions - - - - 1693.7 -29.2 -5.9 2.0 NSW Lower Darling diversions - - - - 54.7 -13.8 -5.6 3.7 VIC Murray diversions - - - - 1655.8 -4.9 0.9 1.9 SA Murray diversions - - - - 665.0 -13.6 0.0 2.3 Total Diversions - - - - 4069.1 -16.4 -2.1 2.0 Losses Total net evaporation 442.4 -8.7 -1.6 10.6 599.5 -9.8 -2.0 10.8 Net groundwater loss - - - - 47.0 0.0 0.0 0.0 Environmental loss - - - - 57.6 -41.5 0.8 4.4 Total loss including SA 3633.3 -15.8 -4.7 5.6 2595.9 -16.1 -5.4 5.6 Total Losses 4075.7 -15.0 -4.4 6.1 3300.1 -15.2 -4.6 6.4 Outflows Barrage outflow 12503.4 -31.9 -12.2 6.4 5105.4 -57.5 -24.9 11.9 Unattributed Flux (GL) Total Unattributed Flux (GL) 0.00 - - - 0.11 - - -

5 WHOLE OF BASIN

Water balances for the Murray-Darling Basin as a whole are presented in Table 21. The total inflows are calculated as the sum of the local inflows to the various systems (i.e. excluding inflows from upstream systems). These are relatively large uncertainties on the local inflows to the Barwon-Darling system, due to the way in which the models have been linked. The links are based on the most downstream reliable gauge on the tributary (MDBA, 2010a), and floodplain flows bypassing these gauges are included in the local Barwon-Darling inflows. This results in relatively small local inflows to the Barwon-Darling under Baseline Conditions and hence, the difference between the Without Development and Baseline inflows is not an accurate representation of the difference in total inflows to the Murray-Darling system, which have increased due to Snowy and Glenelg River transfers. However, the climate change impacts on the total Murray-Darling system inflows, are consistent between the Without Development and Baseline scenarios, and show a decrease of 26% and 10% for the Dry and Median climate scenarios and an increase of 12% for the Wet scenario.

The total diversions in the basin under the historical climate are 10719 GL/y, which is 37% of the total Baseline inflows. While the annual average diversions are expected decrease under the Dry and Median climate scenarios, they would represent an increased proportion of the total inflows for the respective scenarios, i.e. 43% (Dry) and 40% (Median) (Table 23). Under the Wet climate scenario the total diversions are expected to increase by 3%, but would represent a smaller proportion of inflows (34%). On the other hand, under Baseline Conditions, the end of system (Barrage) flows are 5105 GL/y, which corresponds to 18% of total inflows. These are expected to change to 10%, 15% and 18% of inflows under the Dry, Median and Wet climate scenarios (Table 23).

It is clear that under current water sharing arrangements, a reduction of inflows will result in an increased proportion being used for consumptive use, at the expense of the proportion of inflows that will reach the Barrages. In other words, under current conditions the environment will be more affected by climate change than the diversions.

TABLE 21 WATER BALANCE FOR WHOLE OF MURRAY DARLING BASIN FOR PREDEVELOPMENT AND BASELINE SCENARIOS

Model Run Nos 566 705 706 707 580 708 709 710 Scenario Without Development Baseline Water Balance Historical 2030 Dry 2030 Median 2030 Wet Historical 2030 Dry 2030 Median 2030 Wet (GL/y) (%) (%) (%) (GL/y) (%) (%) (%) Total Change in Storage -19.3 -3.0 1.1 -6.5 -143.5 -0.3 0.8 -2.5 Total Inflows 28574.0 -26.1 -9.5 11.9 28860.9 -26.1 -9.2 11.4 Total Diversions 0.0 - - - 10718.7 -14.7 -3.4 3.3 Total Losses 15798.0 -21.1 -7.3 16.2 12886.9 -22.8 -7.7 17.7 Total End of System Outflow (Barrages) 12503.4 -31.9 -12.2 6.4 5105.4 -57.5 -24.9 11.9 Unattributed Flux (GL) 292.0 - - - 293.3 - - -

TABLE 22 SUMMARY OF WITHOUT DEVELOPMENT INFLOWS FOR HISTORICAL CLIMATE AND ESTIMATED % CHANGE FOR DRY, MEDIAN AND WET CLIMATE CHANGE SCENARIOS.

Model Run Nos 566 705 706 707 Scenario Without Development Historical (GL/y) 2030 Dry (%) 2030 Median 2030 Wet (%) Total inflows (%) Paroo 678 -18 -1 30 Warrego 616 -24 -3 33 Nebine 94 -31 -10 40 Condamine-Balonne 1707 -21 -9 12 Moonie 151 -22 -10 17 Border Rivers 2002 -22 -10 10 Gwydir 996 -24 -9 24 Namoi 1883 -19 -5 33 Macquarie-Castlereagh 2859 -21 -8 24 Barwon-Darling 4689 -23 -8 25 Lachlan 1424 -28 -12 8 Murrumbidgee 4236 -24 -13 0 Ovens 1753 -31 -12 1 Goulburn-Broken 3378 -32 -13 -2 Campaspe 290 -38 -16 -4 Loddon 255 -45 -15 -9 Wimmera 248 -45 -14 -3 Murray 16566 -28 -11 5 Whole of Basin 28574 -26 -9 12

Diversions End of system flow % of inflows Historical Dry Med Wet Historical Dry Med Wet Paroo 0 0 0 0 9 7 9 11 Warrego 8 10 8 7 12 11 12 14 Nebine 7 8 7 6 52 50 52 54 Condamine-Balonne 42 46 44 40 14 13 14 15 Moonie 22 24 23 20 47 44 46 50 Border Rivers 21 24 22 19 26 23 25 27 Gwydir 32 35 32 29 17 17 18 17 Namoi 14 16 15 11 31 29 31 33 Macquarie-Castlereagh 14 16 15 13 25 23 25 28 Barwon-Darling 7 10 8 5 62 61 62 62 Lachlan 20 23 21 19 0 0 0 0 Murrumbidgee 44 52 47 47 34 28 32 31 Ovens 2 3 3 2 97 94 96 97 Goulburn-Broken 47 56 50 48 49 39 45 48 Campaspe 39 56 42 42 54 33 49 50 Loddon 37 48 40 39 49 31 45 47 Wimmera 24 29 25 24 0 0 0 0 Murray 33 41 37 31 41 26 35 43 Whole of Basin 37 43 40 34 18 10 15 18 Figures in this table have been presented in graphs at Appendix 1.

6 ACCOUNTING FOR UNMODELLED INFLOWS AND DIVERSIONS FOR PREPARATION OF THE GUIDE

The Without Development and Baseline model scenarios for historical climate, as presented above, have been used in the development of the Guide to the proposed Basin Plan (MDBA, 2010b) (further referred to as ‘The Guide’). However, the numbers presented in the water balance tables are not the exact same numbers as presented in the Guide, as various post- processing steps have been applied to account for inflows, diversions or losses not included in the models.

The local inflows (i.e. excluding inflows from upstream modelled connected river systems), modelled for Without Development conditions, have been used to determine the total inflows for Basin Planning (MDBA, 2010b; Table 5.1 and Appendix C). The modelled inflows do not include explicit representation of some interceptions (e.g. farm dams and plantation forestry) and some unregulated water course diversions. The diversions from unregulated watercourses are estimates based on crop area surveys and assessed irrigation requirements within NSW (MDBA 2009) and percent adjustment of the modelled component within Victoria (Bewsher, 2006b). These unmodelled diversions (Table 24 and 25) have been reported in Table 4.13 of Volume 2 of the Guide, where they have been referred to as watercourse diversions from ‘Minor unregulated rivers’. In absence of adequate data to correct for these changes over time, it has been assumed that modelled inflows include the full effect of these interceptions and unmodelled water course diversions. The actual total inflows are obtained by adding interceptions and unmodelled diversions to the modelled inflows (Table 24).

In some models there were small differences in flows for Without Development conditions and Baseline conditions. For consistency, inflows under current (Baseline) Conditions used for Basin Planning (MDBA, 2010b; Table 5.2 and Appendix C), are set equal to the Without Development inflows plus transfers from out of the Basin.

The Without Development and Baseline outflows reported in the Guide (MDBA, 2010b) are based on the modelled end of system flows, from the modelled area to the downstream model (or to sea in the case of the Murray). Outflows for the Broken and Lower Darling systems were taken from the GSM and Murray model outputs respectively, but have not been separately reported in the water balance tables.

The Current Diversion Limits (CDLs) used in Basin Planning include Water Course Diversions and Interceptions. The Water Course Diversions presented in the Guide (MDBA 2010b; Table 5.2 and Appendix C) are based on sum of modelled diversions (as presented in the water balance tables) and unmodelled water course diversions (Table 25). For some valleys

64 additional adjustments have been made to account for inter valley transfers (e.g. water savings in the Snowy Hydro Scheme), to account for instream losses not included in the models or if modelled diversions were considered to be inaccurate. These adjustments are shown in Table 25 and are described below. The water course diversions reported for ‘Regulated and major unregulated rivers’ in Table 4.13 of Volume 2 of the Guide are based on the modelled diversions, including the adjustments. The diversions from ’Minor unregulated rivers’ correspond to the unmodelled diversions.

The ‘Water used by environment and losses’ as reported in Appendix C of the Guide (MDBA, 2010b; Tables 5.1 and 5.5) has been calculated as the difference between inflows minus outflows and diversions.

There are a few exceptions to these general methods, which are described below.

Ovens

The Ovens model is not implemented in the IRSMF framework and was only updated to the end of December 2008 (SKM, 2009). The time series of Ovens outflow (i.e. flow at Peechelba), required for input to the Murray model, has been extended to 30 June 2009 based on gauged flow data. The modelled annual average Without Development outflow from the Ovens is 1735.2 GL/y (Table 13). The annual average Ovens outflow based on the extended time series is 1728.2 GL/y and is thus 7 GL/y smaller. Therefore the modelled inflows for the period July 1895 to Dec 2009 have been reduced by 7 GL/y, from 1753 GL/yr (Table 13) to 1746 GL/yr (‘Modelled inflows’ in Table 24).

Accordingly, the modelled Ovens outflow for the period July 1895 to Dec 2009 for Baseline Conditions is 1715.0 GL/y (Table 13), but the extended Peechelba flows (July 1895 to June 2009) for the Baseline Conditions is 1708 GL/y.

Goulburn

The Goulburn Simulation Model (GSM) for Without Development Conditions does not include any estimate of losses along the Goulburn River (the loss estimate presented in Table 14 is for the Broken River). The GSM Baseline model only includes a loss estimate for the upper Goulburn river (upstream of Goulburn Weir) and not for the lower part of the river including the Lower Goulburn Floodplain. Therefore, the outflows for the Goulburn River were adjusted, based on an estimated river loss of 300 GL/y for Without Development Conditions and 200 GL/y for Baseline conditions, which results in outflows of 3259 GL/y for Without Development Conditions and 1600 GL/y for the Baseline Conditions. These loss estimates are rough estimates based on losses experienced in other rivers for similar river reaches and require validation with more detailed analysis.

Campaspe

The end of system flow for the Campaspe has been reported in The Guide based on end of system flow from Campaspe to the Murray, which includes private diversions between Rochester and confluence with the Murray (153 GL/y). This approach is not consistent with approach adopted for other Victorian river systems. The modelling and accounting of private diversions downstream of the last gauging stations on tributaries contributing to the Murray including Campaspe River is an issue that needs to be addressed. However, these diversions are small overall and were not explicitly included in the Murray model calibrations. A consistent approach for accounting and modelling these diversions between upstream and downstream model needs to be developed as part of River Manager Program.

Wimmera-Avoca

The Without Development inflows for the Wimmera are 248 GL/y (Table 17). As the Avoca model has not been included in the modelling framework, 88 GL/y was added for Avoca inflows (taken from the MDBSY project, CSIRO, 2008g).

Murrumbidgee

The Baseline outflows to the Murray, as reported in the water balance table for the Murrumbidgee (Table 12), are 1545 GL/y excluding TLM water supply. However, TLM Water Recovery was included in the Murrumbidgee model by reducing the entitlements by the water recovered and this water being supplied during the spill events. The TLM Water supplies have been subtracted from the Murrumbidgee water balance reporting and have been dealt with by the use of Murray model call on TLM water based on the environmental water requirements in the Murray system (ignoring supply constraints in the Murrumbidgee for these runs). Therefore, the baseline outflows for the Murrumbidgee in the Guide (1593 GL/y) are based on MSM model estimates of Murrumbidgee inflow (consisting of Murrumbidgee IQQM outflows less Murrumbidgee TLM water supply by Murrumbidgee IQQM plus MSM model call out of TLM water from Murrumbidgee system).

Murray

The local inflows to the Murray are based on the directly and indirectly gauged Murray sub catchments and the Snowy Mountain Hydro Scheme (SMHS) releases (Table 20). The indirectly gauged inflows are 260.2 GL/y. The directly gauged inflows are 4047.1 GL/y, but this figure includes inflows to the Kiewa of 668 GL/y. Under Without Development conditions, the SMHS releases is based on inflows from the Snowy Mountains that would have occurred naturally (616.9 GL/y), while for Baseline Conditions this figure includes the 527 GL/y Snowy transfer (Table 20). The modelled local inflows for the Murray exclude the Kiewa inflows, as the Kiewa has been reported separately (Table 24).

The diversions reported in the water balance table (Table 20) provided total Murray diversions for NSW, Victoria and South Australia, which have been split in diversions upstream and downstream of Wentworth in the Guide. The total Murray diversions in the water balance table also includes the 55 GL/y of Lower Darling diversions, separately reported in the guide.

Adjustments to total diversions (Table 25)

Intersecting Streams: For the Paroo, Warrego, Condamine Balonne, Nebine and Moonie systems, the modelled diversions reported in Table 25 are based on the total Queensland diversions only. Modelled NSW diversions downstream of the Border in these valleys (Total of 9 GL/y) have not used because of the advice from NOW, NSW on the questionable accuracy of these estimates. The Intersecting Streams total water course diversions figure is based on Cap reporting and is 3 GL/y.

Loddon: The Loddon diversions have been adjusted by subtracting 2 GL/y for the Boort Wetland diversions, which is an environmental diversion.

Murrumbidgee: The Murrumbidgee diversions have been adjusted by 88 GL/y for Water for Rivers (LTCE).

Australian Capital Territory (ACT): ACT diversions figure is based on current Cap of 40 GL/y less 1 GL/y for farm dams.

Kiewa: Kiewa diversions have been estimated by MDBC for 1993/94 level of development as part of setting up of the Cap in various valleys (MDBC, 2002b). These diversions are estimated as 11 GL/y.

TABLE 24 MODELLED WITHOUT DEVELOPMENT LOCAL INFLOWS AND ADJUSTMENTS MADE TO DETERMINE TOTAL INFLOWS (AS REPORTED IN THE GUIDE TO THE BASIN PLAN), (ALL FIGURES ARE IN GL/Y).

Modelled Un- Other Inflows Intercep- Total Region/SDL area modelled adjust- (Without tions Inflows diversions(1) ments Develop.)

Darling and Tributaries Paroo 678 10 688 Warrego 616 85(2) 702 Condamine-Balonne Region 1745 290 2035 Condamine-Balonne local inflows 1651 265 1916 Nebine SDL area 94(3) 25 119 Moonie 151 51 202 Border Rivers (total) 2002 19 174 2195 Border River (Qld) 78 Border River (NSW) 19 95 Gwydir 996 10 125 1131 Namoi 1885 78 165 2128 Macquarie-Castlereagh 2859 45 310 3214 Barwon-Darling local inflows 1138 108 1247 Lower Darling 6 6 Total for Darling including tributaries 12071 152 1324 13547 Murray and tributaries upstream of Wenthworth (excluding Darling) Disconnected Tributaries Lachlan 1424 15 316 1755 Wimmera-Avoca 336 1 62 399 Total for disconnected tributaries 1760 16 378 2155 Connected Tributaries Ovens 1746 58 1804 Goulburn-Broken region 3378 30 152 3559 Goulburn 29 109

Broken 1 43

Loddon 255 2 90 347 Campaspe 290 3 40 333 Murrumbidgee region 4236 42 513(4) 4791 Kiewa 668 14 7(5) 689 Total for tributaries contributing to Murray (excl. Darling) 10573 76 868 7 11523 Murray local inflows u/s Wentworth 4256 28 153(6) 4436 Total for Murray including all tributaries except Darling 14829 104 1020 7 15959 Murray downstream of Wentworth Murray d/s Wentworth Eastern Mount Lofty Ranges 120 (7) 120 Basin Total 28780 272 2722(7) 7 31781 (1) Referred to as ‘Minor unregulated rivers’ in table 4.13 of Volume 2 of the Guide to the proposed Basin Plan (2) This figure includes 2.4 GL/y of Intersecting streams interceptions. (3) Includes 4 GL inflows from Warrego catchment (4) Includes ACT (5) Allowance for losses in the Kiewa River system (6) This figure includes 3.5 GL/y for ‘SA non-prescribed area’, which has been excluded from Interception figures provided in the guide. However, the inflows and diversions are based on this estimate. (7) Does not include 13 GL of Eastern Mount Lofty Ranges because it is already taken care of by inflows.

TABLE 25 MODELLED DIVERSIONS AND ADJUSTMENTS MADE TO DETERMINE THE TOTAL WATER COURSE DIVERSIONS FOR THE CURRENT DIVERSIONS LIMITS (CDL WCDS) AS DESCRIBED IN THE GUIDE (MDBA, 2010B)

Total Water Modelled Unmodelled Other Region/SDL area Course diversions(1) diversions(2) adjustments(1) Diversions Darling and Tributaries Paroo 0.2 0.2 Warrego 45 45 Condamine-Balonne Region 712 712 Condamine-Balonne 706 706 Nebine SDL area 6 6 Moonie 32(3) 32 Intersecting Streams 9 -6 3 Border Rivers (total) 414 19 433 Border River (Qld) 223 223 Border River (NSW) 191 19 210 Gwydir 316 10 326 Namoi 265 78 343 Macquarie Castlereagh 380 45 425 Barwon-Darling 197 197 Lower Darling 55 55 Murray and tributaries upstream of Wentworth (excluding Darling) Disconnected Tributaries Lachlan 287 15 302 Wimmera-Avoca 73 1 74 Connected Tributaries Ovens 25 25 Goulburn-Broken region 1577 30 1607 Goulburn 1564 29 1593 Broken 13 1 14 Loddon 96 2 -2 95 Campaspe 112 3 115 Murrumbidgee region 2107 81 -88 2100 Murrumbidgee 2107 42 -88 2061 ACT 39 39 Kiewa 11 11 Murray u/s Wentworth 3311 28 3338 Murray u/s Hume (NSW) 0 28 28 Murray d/s Hume (NSW) 1679 1679 Mitta Mitta (Victoria) 15 15 Murray d/s Hume (Victoria) 1616 1616 Murray downstream of Wentworth Murray d/s Wentworth 704 704 Murray (NSW) 14 14 Murray (Victoria) 25 25 Murray (SA) 665 665 EMLR / Marne Saunders 0 Basin Total 10718 314 -88 10942 (1) The ‘Regulated and major unregulated rivers’ presented in Table 4.13 of Volume 2 of the Guide are based on the ‘Modelled Diversions’ after the adjustments under ‘Other Adjustments’ have been applied. (2) Referred to as ‘Minor unregulated rivers’ in table 4.13 (p. 181) of Volume 2 of the Guide to the proposed Basin Plan. (3) Includes Commonwealth environmental Water Holder entitlement and is inconsistent with approach adopted for other valleys. This needs to be made consistent in next update.

7 PUBLISHED NUMBERS

The numbers published in this report for various water balance terms (i.e. diversions, losses, inflows or end of system flows) for various catchments may be different to those published from time to time in reports from MDBA, States, CSIRO or other consultants for the purposes of Cap or Water Sharing Plans/Resource Operations Plan/Bulk Entitlements. There are number of reasons for which these could be different and these reasons vary from valley to valley. The key reasons for the differences are:

1. The Basin Plan modelling has been undertaken using the climatic data for the period July 1895 to June 2009. This was the common period for which all 24 river systems models had climate data available. Numbers published by MDBA, States, CSIRO or consultants for various river systems are not for this period and usually results are based on longest period for which data was available for individual river system. 2. Models were updated to include permanent inter State and intra State water trade. 3. Models were updated to include water recovered for the TLM and Water for Rivers (for provision of environmental flows to Snowy and Murray) and its use for the environmental works and measures. 4. Any improvements or updating of models carried by States/MDBA since development of Water Sharing Plans in NSW, Water Resource Plans/Resource Operations Plans in Queensland or Bulk entitlement in Victoria were adopted in the Basin Plan version of models. 5. Best available estimates for impact of groundwater use on the river systems flows at 2030 has been included in the Lachlan (17.4 GL/y), Namoi (11.2 GL/y) and Murray (47 GL/y) models. 6. Some model calibrations have been improved since the versions used for development of various water sharing arrangements in the past and these updated models have been used for the Basin Planning purposes.

8 CONCLUSIONS

This report presents the water balances for Without Development and Baseline scenarios, for historical climate and for the Dry, Median and Wet 2030 climate change scenarios. The main considerations and conclusions are listed below:

1. The Without Development models are based on the models for Baseline Conditions, from which the infrastructure for water storages, channel systems and consumptive demands have been removed. These models are not necessarily a representation of pre-European conditions as inflow estimates have not been corrected for land use changes in the catchments. Moreover, the impact of changes due to levee construction and other in channel structures, on flows in anabranch systems, has not been considered.

2. The Baseline models represent current diversions as permitted by existing transitional and interim water resource plans, where these are in place, or by the Murray Darling Basin Ministerial (MDBM) Cap. The Victorian and Murray diversions are limited to the Cap for these valleys, while NSW and Queensland valley Baseline Conditions are based on Water Sharing Plans and Resource Operations Plans respectively, except the Barwon Darling for which diversions are based on the MDBM Cap.

3. Under the Dry and Median climate change scenarios, inflows are expected to decrease in all systems, with the largest decreases expected in the Southern systems (Table 22). For the Dry climate change scenario, decreases range from -18% in the Paroo system to -45% in the Loddon and Wimmera systems. For the Median scenario, decreases range from -1% in the Paroo system to -16% in the Campaspe. For the Wet climate change scenario, the inflows in the Northern systems may increase, up to a 40% increase in the Nebine system. However, in the Victorian systems, inflows are expected to decrease even under the Wet climate change scenario (Table 22).

4. In Southern systems of Goulburn-Broken, Campaspe, Loddon and Wimmera, inflows are expected to reduce between 2% to 45% under the three climate change scenarios of 2030 Dry, 2030 Median and 2030 Wet. The estimates corresponding to Median is for a reduction of 13% for the Goulburn Broken system, 16% for the Campaspe system and 15% for the Loddon system. (Table 22)

5. For the Murray system, the inflows could vary between a reduction of 28% and an increase of 6% with the Median estimate being a 10% reduction in system inflows. The Murrumbidgee system too has a similar variability, from a reduction of 24% to

an increase of 10%, with a reduction of 9% for the Median climate scenario. (Table 22).

6. For the Murray Darling Basin as a whole, the impact of climate change on the Without Development inflows could range from a reduction of 26% under the Dry extreme to an increase of 12% under the Wet extreme, with a reduction of 10% under the Median scenario (Table 22). Under Baseline Conditions, the end of system flow (at the Barrages) is 5105 GL/y, which is 41% of the Without Development end of system flow, and these are expected to change by -58%, -25% and 12% for the Dry, Median and Wet climate change scenarios, respectively.

7. Generally, under the current water sharing arrangements (Baseline Conditions), a reduction of inflows results in an increase of the proportion of inflows used for diversions, while the proportion of inflows that will reach the end of system will be reduced (Table 23, Appendix 1). In other words, the impact of climate change will be borne more by environment as compared to consumptive use, especially in the Southern part of the basin.

9 REFERENCES

Bewsher D. (2002a), Gwydir Valley, Independent Audit of Cap Model, Prepared for the Murray- Darling Basin Commission, Bewsher Consulting Pty Ltd, April 2009. Bewsher D. (2002b), Lachlan Valley Independent Audit of Cap Model, Prepared for the Murray- Darling Basin Commission, Bewsher Consulting Pty Ltd, August 2002. Bewsher D. (2006a), Namoi Valley, Independent Audit of Cap Model, Prepared for the Murray- Darling Basin Commission, Bewsher Consulting Pty Ltd, 2006. Bewsher D. (2006b), Goulburn/Broken/Loddon and Campaspe valleys, Independent Audit of Cap Model, Bewsher Consulting Pty Ltd, December 2006 Bewsher D. (2007), Macquarie Valley, Independent Audit of Cap Model, Prepared for the Murray- Darling Basin Commission, Bewsher Consulting Pty Ltd, 2007. Bewsher D. (2009), Peel Valley IQQM, Independent Audit of Cap Model, Prepared for the Murray- Darling Basin Commission. March 2009. Bewsher D. (2010), Paroo, Warrego, Nebine and Moonie Valleys Independent Audit of Cap Models Final Report, Prepared for the Murray-Darling Basin Commission, Bewsher Consulting Pty Ltd, December 2009. Bewsher (2008), Victorian Murray, NSW Murray and Lower Darling valleys, Independent Audit of Cap Model, Bewsher Consulting Ltd, 30 June 2008. Chiew FHS, Cai W and Smith IN (2009a), Advice on defining climate scenarios for use in the Murray- Darling Basin Authority Basin Plan modelling, CSIRO report for the Murray-Darling Basin Authority. Chiew FHS, Teng J, Vaze J, Post DA, Perraud J-M, Kirono DGC and Viney NR (2009b), Estimating climate change impact on runoff across south-east Australia: method, results and implications of modelling method. Water Resources Research, 45, W10414, doi:10.1029/2008WR007338. Chiew FHS, Teng J, Kirono D, Frost AJ, Bathols JM, Vaze J, Viney NR, Young WJ, Hennessy KJ and Cai WJ (2008a), Climate data for hydrologic scenario modelling across the Murray-Darling Basin, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia, 42 pp. (ISSN 1835-095X), http://www.csiro.au/resources/HydrologicScenarioModellingMDBSY.html. Chiew FHS, Vaze J, Viney NR, Jordan PW, Perraud J-M, Zhang L, Teng J, Young WJ, Penaarancibia J, Morden RA, Freebairn A, Austin J, Hill PI, Wiesenfeld CR and Murphy R (2008b), Rainfall-runoff modelling across the Murray-Darling Basin, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia, 70 pp. (ISSN 1835- 095X), http://www.csiro.au/resources/Rainfall-runoffModellingMDBSY.html. Commonwealth of Australia (2007), Water ACT. An up-to-date electronic compilation of this Act is available at http://www.comlaw.gov.au. CSIRO and Australian Bureau of Meteorology (2007), Climate Change in Australia. Technical report. http//www.climatechangeinaustralia.gov.au. CSIRO (2007a), Water availability in the Border Rivers, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 144pp. CSIRO (2007b), Water availability in the Namoi, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 154pp.

CSIRO (2007c), Water availability in the Paroo, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 88pp. CSIRO (2007d), Water availability in the Warrego, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 89pp. CSIRO (2007e), Water Availability in the Wimmera, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 108pp. CSIRO (2008a), Water availability in the Barwon-Darling, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 106pp. CSIRO (2008b), Water availability in the Campaspe, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 120pp. CSIRO (2008c), Water Availability in the Condamine-Balonne, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 169pp. CSIRO (2008d), Water availability in the Goulburn-Broken, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 132pp. CSIRO (2008e), Water availability in the Gwydir, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 134pp. CSIRO (2008f), Water availability in the Lachlan, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 133pp. CSIRO (2008g), Water availability in the Loddon-Avoca, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 132pp. CSIRO (2008h) Water availability in the Macquarie-Castlereagh. A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 144pp. CSIRO (2008i), Water availability in the Moonie. A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 79pp. CSIRO (2008j), Water Availability in the Murray, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 217pp. CSIRO (2008k), Water Availability in the Murray-Darling Basin, A report from CSIRO to the Australian Government. CSIRO, Canberra, Australia. CSIRO, Australia .67pp. CSIRO (2008l), Water Availability in the Murrumbidgee, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 155pp. CSIRO (2008m), Water availability in the Ovens, A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO, Australia. 100pp. DECCW (2010) Water Sharing Plan for the Peel Valley Regulated, Unregulated, Alluvium and Fractured Rock Water Sources 2010, NSW Office of Water, Department of Environment, Climate Change and Water, Sydney, NSW. DERM (2006a), Warrego, Paroo, Bulloo and Nebine, Resource Operations Plan. Department of Natural Resources & Mines, Queensland, January 2006. DERM (2006b), Paroo River Daily IQQM ROP Scenario Modelling Description, System Hydrology Reports (Water Resource Plan), prepared by Surface Water Assessment Group for Resource Management, Department of Natural Resources & Mines, Queensland, August 2006.

DERM (2006c), Warrego River Daily IQQM ROP Scenario Modelling Description, System Hydrology Reports (Water Resource Plan), prepared by Surface Water Assessment Group for Resource Management, Department of Natural Resources & Mines, Queensland, May 2006. DERM (2006d), Moonie River Daily IQQM ROP Scenario Modelling Description, System Hydrology Reports (Water Resource Plan), prepared by Surface Water Assessment Group for Resource Management, Department of Natural Resources & Mines, Queensland, May 2006. DERM (2006e), Nebine System Daily IQQM ROP Scenario Modelling Description, System Hydrology Reports (Water Resource Plan), prepared by Surface Water Assessment Group for Resource Management, Department of Natural Resources & Mines, Queensland, May 2006. DERM (2008a), Cap proposal for the Border Rivers valley, Department of Natural Resources & Mines, Queensland, September 2008. DERM (2008b), Moonie Resource Operations Plan, Department of Natural Resources & Mines, Queensland, Reprinted as in Force on February 2006. DERM (2008c), Condamine and Balonne Resource Operations Plan, Department of Natural Resources & Mines, December 2008. DIPNR (2004a), A Guide to the Water Sharing Plan for the Gwydir Regulated River Water Source, Department of Infrastructure, Planning and Natural Resources, NSW, September 2004. DIPNR (2004b), Water Sharing Plan for the Macquarie and Cudgegong Regulated Rivers Water Source 2003. Effective 1 July 2004 and ceases ten years after that date. Department of Infrastructure, Planning and natural resources, Sydney. NSW Government Gazette. DIPNR (2004c), Water Sharing Plan for the Castlereagh River above Binnaway Water Source 2003. Effective 1 July 2004 and ceases ten years after that date. Department of Infrastructure, Planning and natural resources, Sydney. NSW Government Gazette. DIPNR (2004d), Namoi River Valley IQQM Cap Implementation Summary Report. Department of Infrastructure, Planning and Natural Resources, Sydney NSW

DIPNR (2004e), A guide to the Water Sharing Plan for the Lachlan Regulated River Water Source. Department of Infrastructure, Planning and Natural Resources, NSW, September 2004.

DIPNR (2004f). A guide to the water sharing plan for the Murrumbidgee Regulated River Water Source. Department if Infrastructure, Planning and Natural Resources, NSW September 2004. DLWC (1995), Integrated Quantity-Quality Model (IQQM), Reference Manual. NSW Department of Land & Water Conservation, Report No. TS94.048. DLWC (2002), Lachlan River Valley IQQM Cap implementation Summary report, NSW Department of Land and Water Conservation, October 2002 DNR (2006a), Barwon-Darling River Valley IQQM Implementation Calibration Summary Report, Water Management Division, NSW Department of Natural Resources, September 2006. DNR (2006b), Macquarie River Valley IQQM Cap Implementation Summary Report. New South Wales, Department of Natural Resources, 2006. DNR (2006c), Peel River Valley IQQM Cap Implementation Summary Report, NSW Department of Natural Resources, April 2006. DNR (2009), Gwydir River Valley IQQM Cap Implementation Summary Report, Department of Natural Resources, NSW, April 2009.

DSE (2005), Goulburn Simulation Model - Calibration for the Murray Darling Basin Cap, Victorian Department of Sustainability and Environment, August 2005 DSE (2007), Upgrade of Campaspe Valley cap model, Victorian Department of Sustainability and Environment. DSE (2010), Victorian Water Register, Department of Sustainability and Environment, The State of Victoria, http://www.waterregister.vic.gov.au/Default.aspx, Last accessed October 2010. DWE (2007), Murrumbidgee River Valley, IQQM Cap Implementation Summary Report, NSW Department of Water and Energy, August 2007. DWE (2009), Water Sharing in the Murrumbidgee Regulated River, Progress Report 2004 to 2008, NSW Department of Water and Energy, May 2009. Hameed T. and Podger G. (2002), Use of IQQM Simulation Model for Planning and Management of a Regulated River System. In: Integrated Water Resources Management (Proceedings of a symposium held at Davis, California in April 2000). IAHS Publ. no. 272, 2001 IPCC (2007), Climate Change 2007: The Physical Basis. Contributions of Working Group 1 to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. http://www.ipcc.ch. MDBA (2009), Review of Cap Implementation 2008-09. MDBA Publication No. 45/09. MDBA (2010a), Basin Plan Model Linkages. Murray-Darling Basin Authority, Technical Report 2010/18. MDBA (2010b), Guide to the proposed Basin Plan: overview, Murray Darling Basin Authority, Canberra. MDBA Publication no 60/10.

MDBC (2002a), Setting up of MSM-BIGMOD modelling Suite for the River Murray System, Murray Darling Basin Commission, MDBC Technical Report 2002/5. MDBC (2002b), Derivation of Kiewa Catchment Inflows, MDBC Technical Report 2002/6. MDBC (2006a) Review of the Interim Operating Rules for the Barmah-Millewa Forest Environmental Water Allocation: Part 1, MDBC Technical Report No. 2006/4. MDBC (2006b) Revised Operating Rules for the Barmah-Millewa Forest Environmental Water Allocation, MDBC Technical Report No. 2006/13. MDBC (2007), Setting up of the Murray Simulation Model (MSM) for Auditing the CAP in the Murray and Lower Darling River Systems, Murray Darling Basin Commission, Technical Report No. 2006/11. Perera B.J.C. and James B. (2003), A Generalised Water Supply Simulation Computer Software Package, Hydrology Journal, 26, 67-83, 2003. Post DA, Chiew FHS, Vaze J, Teng J and Perraud JM (2008), Future runoff projections (~2030) for southeast Australia. South Eastern Australian Climate Initiative Report, 32 pp. http://www2.mdbc.gov.au/subs/seaci/docs/reports/SEACI_RunoffProjections.pdf. SKM (2008), Ovens REALM Model Review - Model review and revision report, Sinclair Knight Merz, June 2008. SKM (2009a), Goulburn Simulation Model Update of Inputs 2009, Sinclair Knight Merz, October 2009. SKM (2009b), Ovens River REALM model, 2009 Update of Inputs. Sinclair Knight Merz, June 2009.

Vaze J, Chiew FHS, Perraud JM, Viney NR, Post DA, Teng J, Wang B, Lerat J and Goswami M (2010), Rainfall-runoff modelling across southeast Australia: datasets, models and results. Submitted. Viney NR, Perraud J, Vaze J, Chiew FHS, Post DA and Yang A (2009), The usefulness of bias constraints in model calibration for regionalisation to ungauged catchments. In: 18th World IMACS Congress and MODSIM09 International Congress on Modelling and Simulation, Modelling and Simulation Society of Australian and New Zealand and International Association for Mathematics and Computers in Simulation, Cairns, July 2009, http://www.mssanz.org.au/modsim09, (ISBN 978-0-9758400-7-8), pp. 3421–3427. WAMC (2002), Snowy Water Licence, Issued under Part 5 of the Snowy Hydro Corporatisation ACT 1997 (NSW). Available at: http://www.naturalresources.nsw.gov.au/water/pdf/lic_snowy_water_licence.pdf Webster I.T. (2007), Hydrodynamic Modelling of the Coorong. Water for a Healthy Country National Research Flagship, CSIRO. W&D (2009), Murray-Darling Basin Cap Model Accreditation Submission - Wimmera-Mallee Cap River Valley, W&D Engineering and Legal Services, Grampians Wimmera Mallee Water Corporation (GWMWater), October 2009. Yang, A. (2010), The Integrated River System Modelling Framework. A report to the Murray-Darling Basin Authority. CSIRO: Water for a Healthy Country National Research Flagship, Canberra, June 2010.

APPENDIX 1 MODELLED DIVERSIONS AND END OF SYSTEM FLOWS AS PERCENTAGE OF INFLOWS, FOR BASELINE SCENARIOS WITH HISTORICAL AND 2030 DRY, MEDIAN AND WET CLIMATE.

Paroo Warrego Nebine Diversions and 100% 100% 100% 90% 90% 90% End of System 80% 80% 80% Flow as 70% 70% 70% proportion of 60% H 60% H 60% H Inflows under 50% 50% 50% D D D Historical and 40% 40% 40% M M M Climate Change 30% 30% 30% W W W Scenarios 20% 20% 20% 10% 10% 10% 0% 0% 0% Diversions EOS Diversions EOS Diversions EOS

Condamine Balonne Moonie Border Rivers 100% 100% 100% 90% 90% 90% 80% 80% 80% 70% 70% 70%

60% H 60% H 60% H 50% 50% 50% D D D Legend: 40% 40% 40% M M M 30% 30% 30% W W W Historical 20% 20% 20% 2030 Dry 10% 10% 10% 0% 0% 0% 2030 Median Diversions EOS Diversions EOS Diversions EOS 2030 Wet

Gwydir Namoi Macquarie-Castlereagh 100% 100% 100% 90% 90% 90% 80% 80% 80% 70% 70% 70% 60% H 60% H 60% H 50% 50% 50% 1. D D D 40% 40% 40% M M M 30% 30% 30% W W W 20% 20% 20% 10% 10% 10% 0% 0% 0% 78 Diversions EOS Diversions EOS Diversions EOS

Barwon-Darling Lachlan Murrumbidgee 100% 100% 100% 90% 90% 90% 80% 80% 80% 70% 70% 70%

60% H 60% H 60% H 50% 50% 50% D D D 40% 40% 40% M M M 30% 30% 30% W W W 20% 20% 20% 10% 10% 10% 0% 0% 0% Diversions EOS Diversions EOS Diversions EOS

Ovens Goulburn Campaspe 100% 100% 100% 90% 90% 90% 80% 80% 80% 70% 70% 70%

60% H 60% H 60% H 50% 50% 50% D D D 40% 40% 40% M M M 30% 30% 30% W W W 20% 20% 20% 10% 10% 10% 0% 0% 0% Diversions EOS Diversions EOS Diversions EOS

Loddon Wimmera Murray Legend: 100% 100% 100% 90% 90% 90% Historical 80% 80% 80% 70% 70% 70% 2030 Dry 60% H 60% H 60% H 50% 50% 50% 2030 Median D D D 40% 40% 40% 2030 Wet M M M 30% 30% 30% W W W 20% 20% 20% 10% 10% 10% 0% 0% 0% Diversions EOS Diversions EOS Diversions EOS 79

2. Water resource assessments for without-development and baseline conditions Supporting information for the preparation of proposed Basin Plan

Murray–Darling Basin Authority technical report 2010/20 Version 2 November 2011

www.mdba.gov.au Murray–Darling Basin Authority

© Copyright Commonwealth of Australia 2011. This work is copyright. With the exception of the photographs, any logo or emblem, and any trademarks, the work may be stored, retrieved and reproduced in whole or in part, provided that it is not sold or used for commercial benefit. Any reproduction of information from this work must acknowledge the Murray–Darling Basin Authority, the Commonwealth of Australia or the relevant third party, as appropriate, as the owner of copyright in any selected material or information. Apart from any use permitted under the Copyright Act 1968 (Cwlth) or above, no part of this work may be reproduced by any process without prior written permission from the Commonwealth. Requests and inquiries concerning reproduction and rights should be addressed to the MDBA Copyright Administration, Murray–Darling Basin Authority, GPO Box 1801, Canberra City, ACT 2601 or by contacting + 61 2 6279 0100.

Disclaimer This document has been prepared by the Murray–Darling Basin Authority for Technical users with good understanding of strengths and limitations of mathematical modelling, hydrological data and its analysis and interpretation. The information in the report also uses software and/or data provided by other agencies. The Authority and these agencies give no warranty for the data or the software (including its accuracy, reliability, completeness, currency or suitability) and accept no liability for any loss, damage or costs (including consequential damage) incurred in any way (including but not limited to that arising from negligence) in connection with any use or reliance on the data. The opinions, comments and analysis (including those of third parties) expressed in this document are for information purposes only. This document does not indicate the Murray–Darling Basin Authority’s commitment to undertake or implement a particular course of action, and should not be relied upon in relation to any particular action or decision taken. Users should note that developments in Commonwealth policy, input from consultation and other circumstances may result in changes to the approaches set out in this document.

Acknowledgements This report was prepared by the Basin Plan Modelling section of the Murray–Darling Basin Authority (MDBA) based on modelling conducted by the MDBA. The modelling used MDBA models for the River Murray together with models provided by the Victorian Department of Sustainability and Environment, the New South Wales Office of Water, the Queensland Department of Environment and Resource Management, CSIRO and Snowy Hydro Limited. The modelling was undertaken in the Integrated River System Modelling Framework initially developed by CSIRO in the Murray–Darling Basin Sustainable Yields Project and further developed by CSIRO for MDBA for Basin Plan modelling. Cover image: Water testing at Lake Werta Wert in South Australia which received an environmental water allocation in July 2008. (photo by Arthur Mostead © MDBA)

2 CONTENTS 1 Introduction 7 2 Scenarios modelled 9 2.1 Baseline scenario 9 2.2 Without-development scenario 9 3 Water balance terms 9 4 Without-development and baseline scenarios 10 4.1 Paroo 10 4.1.1 Model description 10 4.1.2 Results and discussion 11 4.2 Warrego 12 4.2.1 Model description 12 4.2.2 Results and discussion 12 4.3 Nebine 12 4.3.1 Model description 12 4.3.2 Results and discussion 13 4.4 Condamine–Balonne 14 4.4.1 Model description 14 4.4.2 Results and discussion 17 4.5 Moonie 17 4.5.1 Model description 17 4.5.2 Results and discussion 18 4.6 Border Rivers including Macintyre Brook 18 4.6.1 Model description 18 4.6.2 Results and discussion 19 4.7 Gwydir 20 4.7.1 Model description 20 4.7.2 Results and discussion 21 4.8 Namoi 21 4.8.1 Model description 21 4.8.2 Results and discussion 22 4.9 Macquarie–Castlereagh and Bogan rivers 23 4.9.1 Model description 23 4.9.2 Results and discussion 23 4.10 Barwon–Darling 24 4.10.1 Model description 24 4.10.2 Results and discussion 26

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 3 AND BASELINE CONDITIONS Murray–Darling Basin Authority

4.11 Lachlan 26 4.11.1 Model description 26 4.11.2 Results and discussion 26 4.12 Murrumbidgee 27 4.12.1 Model description 27 4.12.2 Results and discussion 29 4.13 Ovens 30 4.13.1 Model description 30 4.13.2 Results and discussion 31 4.14 Goulburn–Broken, Campaspe and Loddon rivers 31 4.14.1 Model description 31 4.14.2 Results and discussion 33 4.15 Wimmera 35 4.15.2 Model description 35 4.15.2 Results and discussion 36 4.16 Murray 37 4.16.1 Model description 37 4.16.2 Results and discussion 38 5 Unmodelled diversions 43 6 Accounting for unmodelled inflows and diversions for preparation of the proposed Basin Plan 43 7 Published numbers 50 8 References 51 9 Appendix 56

4 LIST OF TABLES Table 1 Water balances for the Paroo system for without-development and baseline scenarios 11 Table 2 Water balances for the Warrego system for without-development and baseline scenarios 13 Table 3 Water balances for the Nebine system for without-development and baseline scenarios 14 Table 4 Water balances for the Condamine–Balonne system for without-development and baseline scenarios 16 Table 5 Water balances for the Moonie system for without-development and baseline scenarios 17 Table 6 Water balances for the Border Rivers and Macintyre Brook system for without-development and baseline scenarios 19 Table 7 Water balances for the Gwydir system for without-development and baseline scenarios 20 Table 8 Water balances for the Namoi and Peel system for without-development and baseline scenarios 22 Table 9 Water balances for the Macquarie–Castlereagh and Bogan River system for without‑development and baseline scenarios 24 Table 10 Water balances for the Barwon–Darling system for without-development and baseline scenarios 25 Table 11 Water balances for the Lachlan system for without-development and baseline scenarios 27 Table 12 Murrumbidgee Water for Rivers purchases 28 Table 13 Murrumbidgee TLM purchases 28 Table 14 Water balances for the Murrumbidgee system for without-development and baseline scenarios 29 Table 15 Water balances for the Ovens system for without-development and baseline scenarios 30 Table 16 Environmental water recovery and trade entitlements included in the GSM baseline model 32 Table 17 Water balances for the Goulburn–Broken system for without-development and baseline scenarios 33 Table 18 Water balances for the Campaspe system for without-development and baseline scenarios 34 Table 19 Water balances for the Loddon system for without-development and baseline scenarios 34 Table 20 Water balances for the Wimmera system for without-development and baseline scenarios 36 Table 21 The Living Murray water recovery projects 39 Table 22 Water for Rivers recovery in the Murray 41 Table 23 Water balances for the Murray system for without-development and baseline scenarios 42 Table 24 Diversions not included in Cap/water sharing models (GL/year) 44 Table 25 Modelled without-development local inflows and additions/adjustments made to determine total inflows as reported in Schedule 1 to the proposed Basin Plan (GL/y) 47 Table 26 Modelled diversions, unmodelled diversions and adjustments made to determine the total watercourse diversions and interceptions added to determine final BDL estimates as presented in the proposed Basin Plan (GL/y) 48

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 5 AND BASELINE CONDITIONS Murray–Darling Basin Authority

ACRONYMS AND TERMS USED REALM — resource allocation model Baseline — modelled scenario representing ROP — resource operations plan development and water management SA — South Australia conditions at June 2009 (refer Section 2.1) SDL — long-term average sustainable Basin —the Murray–Darling Basin diversion limit CEWH — Commonwealth Environmental TLM — The Living Murray Water Holder Water for Rivers — program for water DERM —Department of Environment and recovery for providing environmental flows Resource Management, Queensland for the Snowy River DIPNR — former Department of Without-development — modelled scenario Infrastructure, Planning and Natural representing near natural river system Resources, NSW conditions (refer to Section 2.2) DLWC — former Department of Land and Water Conservation, NSW DNR — former Department of Natural Resources, NSW DSE — Department of Sustainability and Environment, Victoria GL/y — gigalitres per year GS — general security GSM — Goulburn simulation model HRWS — high reliability water share IQQM — integrated quality and quantity model IRSMF — integrated river system modelling framework LRWS — low reliability water share LTCE — long-term Cap equivalent MDBA — Murray–Darling Basin Authority MDBSY —the CSIRO’s Murray–Darling Basin Sustainable Yields project MSM — Bigmod — linked monthly simulation model and daily flow and salinity routing model for the River Murray system NOW — NSW Office of Water, part of the NSW Department of Water and Energy NSW — New South Wales QLD — Queensland

6 1 INTRODUCTION This report has been prepared to explain the origin of data included in Schedule 1 and An understanding of the water balance Schedule 3 of the proposed Basin Plan. It across the Murray–Darling Basin, under also explains the origin of the estimates for various scenarios, is critical information unmodelled diversion and interception data. for the development of a Basin Plan. In 2007–2008, the CSIRO Murray–Darling This report (version 2, MDBA Technical Basin Sustainable Yields (MDBSY) project report 2010/20) has been updated and published a series of reports documenting simplified, relative to version 1, which was water availability across the Murray–Darling prepared to support the release of the Guide Basin (the Basin), including an assessment to the proposed Basin Plan (MDBA 2010b). of the likely impacts of climate change This version no longer includes the results to ~2030 on water availability (e.g. CSIRO of modelled climate change scenarios. 2008k). This assessment was the Note that the numbers presented in the most comprehensive and integrated water balance tables for some river valleys assessment of water availability in the differ from those in MDBA technical report Basin ever undertaken. 2010/20 version 1 due to updates and As part of the technical work supporting revision of models and feedback received the development of the proposed Basin on the Guide to the proposed Basin Plan Plan, the Murray–Darling Basin Authority (MDBA 2010b). (MDBA) (with assistance from CSIRO and A related report ‘Comparison of water its consultants and state governments) course diversion estimates in the proposed has developed Basin-wide modelling Basin Plan with other published estimates’ capability. It has adopted and enhanced (MDBA 2011) explains why numbers the Integrated River System Modelling reported in the water balances in this Framework (IRSMF) developed by CSIRO report may differ from numbers in other (Figure 1). This framework links together previously published reports; including state 24 individual river valley models that have based water sharing plans in NSW, the been developed by state agencies, CSIRO, Cap for Victorian catchments and resource Snowy Hydro Limited and MDBA over the operations plans (ROP) in Queensland. past four decades for water management and policy development. This report presents the water balances for the Basin, derived from the modelling framework. It includes details of the modelled baseline and without-development scenarios, and the resulting water balances for each valley, including inflows and diversions. The model set-up and the data and time series used as inputs encapsulate modelling assumptions, water management policies and water sharing arrangements, which are all part of the baseline for the proposed Basin Plan. This report only provides an overview of model set-up and key assumptions and other documents with more details have been referenced.

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 7 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Figure 1 Integrated River system modelling framework used for Basin Plan development

8 2 SCENARIOS MODELLED Further details of the baseline conditions modelled for each individual valley are The two scenarios used as starting point discussed in Section 4. for the development of the proposed Basin Plan and for setting environmental water 2.2 Without-development requirements are: scenario • baseline scenario The without-development scenario (model • without-development scenario run no. 844) is a near natural condition This report provides an overview of the model run. It is based on the baseline models used for various catchments conditions scenario, from which all of the and presents resulting water balances dams, irrigation and environmental works for without-development and baseline infrastructure and all consumptive users scenarios under the historic climate, over (such as irrigation, town water supply the period July 1895 to June 2009. These and industrial water uses) are removed water balances provide best available from the system. However, these models estimates of annual average inflows, are not necessarily a representation diversions, losses and outflows in the of pre‑European conditions, as inflow system. Time series analysis of the flow estimates have not been corrected for land regimes has been used to assess the use changes and on-farm development environmental water requirements for key in the catchments, which are largely assets and key ecological functions. included implicitly in the calibration of rainfall‑runoff models and measured data 2.1 Baseline scenario used in the models. Moreover, the impact of changes due to levee construction The baseline scenario (model run no. 871) and other in‑channel structures on represents the water sharing arrangements flows in anabranch systems, has not and diversions as permitted by the been considered. transitional and interim water resource plans, where these were in place as at June 2009. It reflects the Murray–Darling 3 WATER BALANCE TERMS Basin ministerial Cap level of development In the following sections, water balances for all states unless current water sharing are presented for the 18 river systems. arrangements have a usage level lower The water balance terms have been than the cap level, e.g. the NSW water presented as: sharing plans. • Change in storage — net change in The water recovery under The Living Murray storage (dams and river channel) (TLM) and Water for Rivers for the Snowy between the start of simulation in July River is included as part of the baseline 1895 and end of simulation in June 2009 conditions but water recovery under other • Inflows — total system inflows programs such as the Commonwealth from gauged and ungauged Government Sustainable Rural Water tributaries (and where relevant Use and Infrastructure and Restoring from modelled tributaries) the Balance in the Murray–Darling Basin • Losses — total system losses including programs, the NSW Government River evaporation losses, river channel losses Environmental Restoration program and anabranches that do not return and the Northern Victorian Irrigation to the river or the downstream river Renewal Program are not included in the system, as such it also includes flow to baseline scenario. terminal lakes or wetlands

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 9 AND BASELINE CONDITIONS Murray–Darling Basin Authority

• Diversions — total diversions from the The MDBA has used the best available modelled system, which are accountable information on system water balances for under the Murray–Darling Basin Cap deriving sustainable diversion limits for the (unless specified otherwise) proposed Basin Plan. • Outflows — the end-of-system flow is the flow from the modelled area to a 4 WITHOUT-DEVELOPMENT downstream model, or to the sea in AND BASELINE the case of the river Murray; for some models, the reported ‘total modelled SCENARIOS outflows’ may include other outflows The following sections present the (e.g. flood breakouts) that need to be key features of the individual without- taken into account for the calculation development and baseline models and of the unattributed flux (or mass the water balance results for without- balance error). development and baseline scenarios under Appendix 1 summarises the above historical climatic conditions. mentioned water balance terms for all Model development, including input data valleys for the without-development and development and model calibration are baseline scenarios (whereby the change in discussed in greater detail in separate storage has been combined with the losses). reports for each river system, which have The water balances presented in this been referenced in this document. report provide our best knowledge of the volumes of water that flow into the river 4.1 Paroo systems, volumes used for consumptive use, volumes flowing into floodplain wetlands, 4.1.1 Model description volumes lost as recharges to groundwater The Paroo River is an ephemeral river, or evaporation, and the volumes that with most of its catchment located in reach the end of the system. The quality Queensland. The Paroo region covers and quantity of available measured flow less than 4% of the total area of the data varies across the Basin, especially Murray–Darling Basin, and has less for tributaries and small streams flowing than 0.1% of the Basin’s population into the main river. Generally, the most (CSIRO 2007c). reliable measured flow data is available for flow measurements along the key gauging The Paroo river system is modelled with stations on the main river. Based on these an Integrated Quantity and Quality Model flow measurements, it is often not possible (IQQM) (DLWC 1995) representing the Paroo to accurately differentiate between inflows to River from the Yarronvale gauge (424202) to the river between two reliable measurement its inflow into the Darling River. Whilst the locations and losses that occur in that river Department of Environment and Resource reach. Therefore, often model estimates of Management, Queensland (DERM) has unmeasured inflows and river system losses included diversions and residual inflows into between reliable gauges on the main river the NSW portions of the Paroo, Warrego, may be over or under estimated. However, Nebine and Moonie IQQMs, DERM considers the confidence in the modelling predictions these representations to be indicative only on the net effect (inflows minus losses) is and advises they should not be relied upon still reasonably high, because of calibration without further verification by the NSW and validation of the models at the reliable Office of Water (NOW). The Paroo system gauges under range of flow conditions. rarely flows to the Barwon–Darling system

10 and in absence of enough data to calibrate 4.1.2 Results and discussion the river system model, the inflows from The water balances for without-development Paroo system to the Barwon–Darling system and baseline conditions for the Paroo are assumed to be zero. system are summarised in Table 1. The The baseline conditions for the Paroo Paroo system does not have many flow system are based on the resource gauges, and only 8% of the river system operations plan (ROP) (DERM 2006a). inflows are measured. The remaining 92% This ROP model version is described in of inflows are estimated using models. detail in a report prepared by DERM (2006b). The total mean annual inflow to the Paroo No changes have been made to the model system is estimated at 678.2 GL/y under for its integration into the MDBA’s integrated without-development conditions. The Paroo river systems modelling framework system has only a very small amount of (IRSMF). The model was audited by Bewsher diversions and is still in pristine condition Consulting (2010a) and was recommended (0.04% of total inflows). for use for setting the Cap and for annual Cap auditing. The audit identified issues with the approximate nature of data available to model overland flows and recommended the submission of a revised model by December 2012.

Table 1 Water balances for the Paroo system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage -1.0 -1.0 Inflows Directly gauged (not included in water balance) 56.6 56.6 Indirectly gauged 621.5 618.7 Total inflows 678.2 675.4 Diversions QLD diversions - 0.19 NSW diversions - 0.10 Total modelled water course diversions - 0.29 Losses Net evaporation from storage 126.9 126.9 Natural water bodies 492.4 489.4 Floodplain losses south of Wanaaring 59.4 59.3 Total losses 678.8 675.6 Outflows QLD to NSW border flow 475.6 475.4 Total outflow to Barwon–Darling 0 0 Unattributed flux Unattributed flux 0.4 0.4

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 11 AND BASELINE CONDITIONS Murray–Darling Basin Authority

4.2 Warrego directly based on the ROP version, which is described in detail in DERM 2006c. This 4.2.1 Model description model assumes that the 8 GL of unallocated water entitlement is used within the The Warrego region covers 7% of the system. The model was audited by Bewsher Basin and is predominantly located in Consulting (2010a) and was recommended Queensland at the northern edge of the for use for setting the Cap and for annual Basin. It is bounded to the east by the Cap auditing. The audit identified issues Condamine–Balonne region and by the with the approximate nature of data Paroo region to the west. The region has available to model overland flows and less than 1% of the Basin’s population recommended that DERM submit a revised (CSIRO 2007d). model by December 2012 after suggested The Warrego River system is modelled using improvements to the model are made. a daily time step IQQM developed by DERM (2006c). The model simulates the Warrego 4.2.2 Results and discussion River system from the Augathella gauge The water balances for the without- (423204) to three terminal points: development and baseline scenarios for the • Ford’s Bridge (gauges 423001 and Warrego system are summarised in Table 2. 423002) draining to the Darling system The Warrego system does not have many • Widgeegoara–Noorama Creeks draining flow gauges, and only 8% of the inflows are to Nebine Creek measured. The remaining 82% of inflows • Cuttaburra Creek draining to the are estimated using models. The total Paroo system. inflows to the Warrego system are 616 The Warrego system in Queensland crosses GL/y, and only a small fraction of these the border into NSW at the following points: (8%) are diverted from the river system. • Warrego River at Barringun Under without-development conditions, 15% (gauge 423003) of the total inflows would reach the Barwon– Darling system. This has decreased to 12% • Widgeegoara–Noorama Creeks at under baseline conditions. the border • Irrara Creek at the border 4.3 Nebine • Cuttaburra Creek at the border. Allan Tannock Weir is the only regulated 4.3.1 Model description storage in the model. The model assumes The Nebine system is a sub-catchment of that inflows into Allan Tannock Weir up to the Condamine–Balonne system (CSIRO 300 ML/day will bypass the weir. There is a 2008c). The Nebine model is an IQQM regulated water supply from Allan Tannock representation of the Nebine River from Weir to two irrigation nodes. The water is the headwater inflows at Wallam Creek, shared between these users via an annual Mungallala Creek and the Nebine River and accounting system. includes inflows from the Warrego River The without-development and baseline through the Widgeegoara and Noorama versions of the model provided by DERM Creeks near the NSW border. The model were developed for the ROP for the Warrego ends at the confluence of Nebine and (DERM 2006a). No changes have been Warrego inflows. The outflows from the made to the model for its integration Nebine are inflows into the lower Balonne into the MDBA’s IRSMF, so the model is system. The Nebine system is unregulated

12 and has no regulated storages, but the data available to model overland flows and model includes nine storages to model the recommended that DERM submit a revised natural water bodies. model by December 2012 after suggested improvements to the model are made. The without-development and baseline version of the models were provided by DERM and were developed for the ROP for 4.3.2 Results and discussion the Nebine (DERM 2006a). No changes have The water balances for without-development been made to the model for its integration in and baseline conditions for the Nebine the MDBA’s IRSMF, so the Nebine baseline system are summarised in Table 3. model used is the ROP version of the The Nebine system does not have any model, described in detail in DERM (2006e). long-term gauges, so all of its inflows are This model includes a 1.1 GL unallocated estimated using models. The total inflows water entitlement, which is assumed to in the Nebine system are 94 GL/y. Under be used within the system. The model was without-development conditions, 59% of audited by Bewsher Consulting (2010a) and inflows would reach the lower Balonne accredited for use for setting the cap and system. This has decreased to 52% under annual cap auditing. The audit identified baseline conditions, with 7% of total inflows issues with the approximate nature of being diverted.

Table 2 Water balances for the Warrego system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage -0.4 -0.4 Inflows Directly gauged 51.0 51.0 Indirectly gauged 565.1 565.1 Total inflows 616.1 616.1 Diversions QLD diversions - 44.7 NSW diversions - 6.9 Total modelled water course diversions - 51.6 Losses Total QLD losses 378.0 356.3 Total NSW losses 148.0 132.3 Total losses 526.1 488.7 Outflows Fords Bridge – outflow to Barwon-Darling 69.4 58.2 Cuttaburra Creek – outflow to Paroo 17.1 14.3 Norooma & Widgeegoara Creek – outfl. to Nebine 3.9 3.7 Total outflows 90.4 76.2 Unattributed flux Unattributed flux 0.02 0.04

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 13 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Table 3 Water balances for the Nebine system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage -0.4 -0.4 Inflows Residual catchment (i.e. indirectly gauged) 93.8 93.6 Total inflows 93.8 93.6 Diversions QLD diversions - 6.2 NSW diversions - 0.0 Total modelled water course diversions - 6.2 Losses Storage evaporation losses 8.5 12.4 River losses 30.9 27.3 Total losses 39.4 39.6 Outflows End-of-system outflows to Condamine–Balonne 55.4 48.9 Unattributed flux Unattributed flux -0.6 -0.8

4.4 Condamine–Balonne The four models have been developed by DERM and are described below. 4.4.1 Model description The baseline models correspond to the ROP for the Condamine–Balonne (DERM, The Condamine–Balonne region (including 2010). The models have been submitted for the Nebine) is predominantly in southern auditing for their accreditation for the Cap Queensland, extends about 100 km to the implementation, but the auditing has not south-west into New South Wales and been completed yet. represents 12.8% of the total area of the Basin. It has 9% of the Basin’s population Upper Condamine model (CSIRO 2008c). The Condamine–Balonne system is modelled using four separate The model represents the upper Condamine models that have been linked together: River from the Condamine headwater • the upper Condamine (UCON) daily time inflows into Killarney Weir to the Condamine step IQQM model River at Cecil Plains Weir gauge (422316A) and the North Condamine River at the Lone • the middle Condamine (MCON) daily Pine gauge (422345A). The outflows from time step IQQM model the upper Condamine are inflows into the • the St. George (STGE) daily time step middle Condamine system. capacity share model The model includes seven in-stream supply • the lower Balonne (LBON) daily time storages; two unregulated (Killarney Weir step IQQM model. and Connolly Dam) and five regulated (Leslie Dam, Talgai Weir, Yarramalong Weir,

14 Lemontree Weir and Cecil Plains Weir). In St. George model addition, off-stream storages for overland The St. George daily model has been flow diversion are also included in the model. built by DERM to simulate the St. George The modelled water use includes Water Supply Scheme (WSS). The model high priority supplemented users, covers a section of the Balonne River from medium priority supplemented users, Beardmore Dam to the St. George Jack unsupplemented users, overland flow Taylor Weir (JTW) gauge (422201). diversion, high priority town water supplies It receives inflows from the middle and high priority stock and domestic users Condamine model and provides outflows in Queensland. The upper Condamine to the Lower Balonne model. system is operated under an annual The St. George water supply scheme accounting scheme with a maximum consists of Beardmore Dam, which allocation level of 100%. is connected to Moolabah weir and Buckinbah weir by the Thuraggi Channel. Middle Condamine model The Beardmore Dam and the three weirs The model represents the middle (JTW, Moolabah and Buckinbah) have Condamine system from Cecil Plains Weir been combined into a single storage in the and Lone Pine gauge to the Beardmore Dam model. The storage-area-volume curve headwater gauge (422212B), including the used for the single storage is adjusted to account for the levels maintained in Maranoa River. The outflows from middle the weirs during normal operation of the Condamine are inflows into the lower combined storages. The model also includes Balonne model for the without-development off-stream storages for water harvesting scenario and inflows into the St. George and overland flow diversion. The system is model for the baseline scenario. modelled using a capacity share scheme by The model has 15 regulated storages (Tipton modelling individual shares in the storage Weir, Cooby Dam, Loudon Weir, Bell Town (CSIRO 2008c). water supply, Jandowae town water supply, Warra Weir, Chinchilla Weir, Condamine Lower Balonne model Weir, Rileys Weir, Tara town water storage, The lower Balonne model represents the Freers Weir, Dogwood Creek Weir, Drillham Balonne, Culgoa and Bokhara rivers with Creek Weir, Surat Weir, and Neil Turner inflows from the St. George and Nebine Weir). The model also has off-stream models and including the Narran River and storages for water harvesting and overland Narran Lakes. flow diversion. The lower Balonne system is unregulated The modelled water use includes and there are no regulated storages in high priority supplemented users, the model. However, the model includes medium priority supplemented users, 14 storages to model the natural water unsupplemented users, overland flow bodies and two large on-river storages diversion, high priority town water that represent private water users. supplies and high priority stock and The model also has storages for water domestic users in Queensland. The middle harvesting and overland flow diversion. Condamine system is operated under two The modelled water use in Queensland annual accounting schemes, both with a includes unsupplemented users, overland maximum allocation level of 100%. flow diversion, and two town water supplies. NSW water use is modelled for unsupplemented users and three town water supplies.

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 15 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Table 4 Water balances for the Condamine–Balonne system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage -0.2 -0.2 Inflows Tributary inflow from Nebine 55.4 48.9 Directly gauged (headwater) 229.5 229.5 Indirectly gauged 1,421.7 1,421.9 Total inflows 1,706.6 1,700.3 Diversions QLD diversions - 713.3 NSW diversions - 1.1 Total modelled water course diversions - 714.5 Losses River losses 976.2 583.2 Net evaporation from storages 161.1 159.1 Total losses 1,137.2 742.4 Outflows Border flows 913.6 380.7 End-of-system total outflows 569.4 241.8 Unattributed flux Unattributed flux 0.2 2.9

Note that there is some overlap between The without-development and baseline the St. George model and the lower Balonne versions of the models were provided by model. The St. George model ends at the DERM and were used for the preparation bifurcation point downstream of JTW, of the ROP for the Condamine–Balonne whereas the lower Balonne model starts (DERM, 2010). The Condamine–Balonne from JTW. This overlap is taken into account baseline model used is the ROP version in the reporting of the results for the of the model. However, subsequent to the Condamine–Balonne system. model runs presented in this report, an updated version of the model has been The lower Balonne model ends at the supplied to MDBA. The Condamine–Balonne following three locations, where it flows into models are being audited by Bewsher the Barwon–Darling system: Consulting for their suitability for setting • Culgoa River downstream of Collerina the Cap and for annual Cap auditing. (gauge 422006) The diversion estimates for the Condamine • Bokhara River downstream of Goodwins will be updated based on recommendations (gauge 422005) of this audit and any changes made as • Narran Lake outflow downstream of a consequence. Narran Park (gauge 422029).

16 4.4.2 Results and discussion 4.5 Moonie The water balances for without-development and baseline conditions for the Condamine– 4.5.1 Model description Balonne system are summarised in The Moonie region is largely in Table 4. The Condamine–Balonne system south‑eastern Queensland to the east of has a limited number of flow gauges on St. George. It covers 1.4% of the total area contributing tributaries, and only 13% of of the Murray–Darling Basin. Its population the inflows are based on gauged data. is less than 0.1% of the Basin total The remaining 87% of inflows are estimated (CSIRO 2008i). using models. The total inflows in the The Moonie River system is modelled Condamine–Balonne system are 1,706 GL/y. using IQQM developed by DERM (2006d). Under without-development conditions The model simulates the Moonie River 33% of the total inflows flows into the system from Nindigully (417201) to Barwon–Darling system. This proportion has Gundablouie (417001). The Moonie River decreased to 14% under baseline conditions, crosses the Queensland–NSW border at a whereby 42% of the inflows is diverted. point up‑stream of Gundablouie.

Table 5 Water balances for the Moonie system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage -0.00 -0.01 Inflows QLD inflows Directly gauged 112.9 112.9 Indirectly gauged 24.2 24.2 Total QLD inflows 137.1 137.1 Total NSW inflows 14.0 14.0 Total inflows 151.1 151.1 Diversions QLD diversions - 33.2 NSW diversions - 0.8 Total modelled watercourse diversions - 34.0 Losses QLD losses 39.2 34.0 NSW losses 15.6 11.8 Total losses 54.8 45.7 Outflows QLD to NSW border flow 97.9 69.9 Gundablouie end-of-system flow to Barwon–Darling 96.3 71.4 Unattributed flux Unattributed flux -0.02 -0.02

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 17 AND BASELINE CONDITIONS Murray–Darling Basin Authority

The without-development and baseline (CSIRO 2007a). The Border Rivers and versions of the models were provided by Macintyre Brook systems are modelled DERM and were developed for the ROP for separately using two models. the Moonie (DERM, 2008b). No changes Macintyre Brook model have been made to the model for its integration in the MDBA’s IRSMF, hence The Macintyre Brooke model simulates the the baseline model used for the Moonie is Macintyre Brook system from Coolmunda the ROP version of the model, described Dam to its confluence with the Dumaresq in detail in DERM (2006d). The 1.2 GL/y of River. The Macintyre Brooke outflows are the unallocated water described in the Moonie total of two modelled outflows, representing Water Resource Plan 2003 (DERM, 2008b) is the regulated and unregulated components included in the model as a diversion. of flow at the Booba Sands gauge (416415). Coolmunda Dam is the only regulated The model was audited by Bewsher storage in the model, in addition to two Consulting (2010a) and was accredited for unregulated weirs, i.e. Whetstone and Ben the implementation and auditing of the Dor. The model is operated under an annual Cap. The audit identified issues with the accounting scheme. Water use as modelled approximate nature of data available to corresponds to Queensland high and model overland flows and recommended medium priority water allocations and town that a revised model be submitted by water supplies. December 2012. Border Rivers model 4.5.2 Results and discussion The Border Rivers model simulates the The water balances for without-development Border Rivers system from the headwater and baseline conditions for the Moonie inflows of Pike Creek into Glenlyon Dam and system are summarised in Table 5 the Severn River (NSW) into Pindari Dam. The water use in Queensland is modelled for The Moonie system is well gauged, such high and medium priority water allocations, that 75% of the river system inflows are unsupplemented water allocations and based on gauged data. The remaining 25% town water supplies and in NSW for of inflows are estimated using models. general security, supplementary access and The total inflows in the Moonie system high security town water supplies. NSW under historical climate are 151 GL/y. supplementary access is constrained by a Under without-development conditions, 120 GL/y Cap. The model is operated under the proportion of inflows that reaches a continuous account scheme. the Barwon–Darling system is 64%. Under baseline conditions, this has been The natural weir pools and floodplains reduced to 47%, whereby 22% of total along the length of the Border Rivers inflows are diverted. are modelled as storages. Pindari Dam, Glenlyon Dam, and Boggabilla Weir are the 4.6 Border Rivers including regulated storages in the model. The model Macintyre Brook also includes unregulated system on-farm storage including overland flow harvesting. 4.6.1 Model description The model includes state sharing of The Border Rivers region straddles the Glenlyon Dam and Boggabilla Weir. There is border between NSW and QLD, and covers also state sharing of inflows and surplus 4% of the area of the Basin. The region has flows. Surplus flows are allocated on a 2.5% of the total population of the Basin

18 state basis and any under-utilised water is The Border Rivers and Macintyre Brook accessible to the other state with a payback models are yet to be audited by Bewsher arrangement in Glenlyon Dam. Consulting for accreditation for use for the Cap implementation. Therefore, estimates of The Border Rivers model feeds into the diversions reported herein may change as a Barwon–Darling system at three locations: consequence of recommendations from the • Mungindi gauge (416001) independent audit of the model. • Neeworra on Boomi River (416028) • the confluence of Little Weir River and 4.6.2 Results and discussion the Barwon River. The water balances for without-development The baseline model as used by MDBA is and baseline conditions for the Border the model corresponding to the Inter- Rivers system (including the Macintyre Government Agreement (IGA) between NSW Brook system) are summarised in Table and QLD. The Border Rivers Cap model, 6. The system has a reasonable number including model calibrations and validations, of flow gauges on the contributing is described in more detail in DERM (2008a). tributaries with 41% of the river system inflows based on gauged data, and 59%

Table 6 Water balances for the Border Rivers and Macintyre Brook system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage 0.13 -0.26 Inflows Directly gauged (headwater) 814.4 814.4 Indirectly gauged 1,188.0 1,187.9 Total inflows 2,002.4 2,002.3 Diversions QLD diversions - 217.5 NSW diversions - 191.3 Total modelled water course diversions - 408.8 Losses River losses 1,191.7 1,038.1 Evaporation from storages 20.7 50.3 Net loss to groundwater -8.7 -8.7 Total losses 1,203.7 1,079.7 Outflows End-of-system in Barwon at Mungindi 539.5 317.0 End-of-system in Boomi at Neewora 215.1 173.4 End-of-system in Little Weir at the confluence 42.8 22.3 Total outflows to Barwon–Darling 797.4 512.6 Unattributed flux Unattributed flux 1.1 1.4

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 19 AND BASELINE CONDITIONS Murray–Darling Basin Authority

estimated using models. The total inflows For regulated parts of Gwydir Catchment for both without-development and baseline a daily time step IQQM model has been conditions are 2,002 GL/y. set up by NOW. The Gwydir model covers the catchments of Gwydir River from For the Border Rivers system (including the Stonybatter gauge (418029) to its confluence Macintyre Brook system) 40% of its total with the Barwon River. Towards the lower inflows would reach the Barwon–Darling end of the Gwydir valley, the model covers system under without-development the floodplains of Mehi River, Mallowa conditions. This has decreased to 26% Creek, Moomin Creek and Carole/Gil under baseline conditions, with 20% of Gil Creeks. The model provides three inflows being diverted. end‑of‑system flows to the Barwon–Darling 4.7 Gwydir model, i.e. Gwydir River at Collymongle gauge (418031), Mehi River at Collarenebri gauge (418055) and Gil Gil Creek at Galloway 4.7.1 Model description gauge (416052), as well as return flows from The Gwydir region is located in the Gingham watercourse. During major north‑eastern NSW and covers 2% of floods, the accuracy of measurements Basin. It has 1.4% of the Basin’s population of flow at these gauges is poor and it is (CSIRO 2008e). believed that some floods bypass these

Table 7 Water balances for the Gwydir system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage - -7.4 Inflows Directly gauged 755.6 755.6 Indirectly gauged 240.5 240.5 Total inflows 996.1 996.1 Diversions Total modelled water course diversions - 314.0 Losses Net evaporation from storage - 23.1 River losses 480.5 370.7 Effluent losses 1,605.7 1,292.4 Effluent returns -1,457.6 -1,170.5 Total losses 628.6 515.7 Outflows Gil Gil Creek 129.0 79.3 Gwydir River at Collymongle 20.6 4.9 Mehi River at Collarenebri 217.9 89.7 Total outflows to Barwon-Darling 367.5 173.9 Unattributed flux Unattributed flux -0.0 -0.1

20 gauges; the estimated flow contributions 4.8 Namoi due to these bypass flows are included in the Barwon–Darling model as additional 4.8.1 Model description floodplain flows. The Namoi region is situated in north- The model used for the Basin Plan eastern New South Wales. It covers 3.8% of modelling is the water sharing plan the total area of the Basin and has 4.5% of version of the model. There is no separate the Basin’s population (CSIRO 2007b). documentation of this model version, but For the regulated parts of the Namoi and environmental flow rules and water sharing Peel catchments, two separate daily time arrangements in the model correspond step IQQM models have been set up by NOW to the Gwydir Water Sharing Plan (DIPNR and have been linked in MDBA’s IRSMF 2004a). However, the Cap model setup modelling framework. The Peel model is described in detail in DNR (2009) covers sub-catchments of the Peel River and this report provides information on from headwater inflows into the Dungowan model calibration and validation details of Dam to its confluence with the Namoi River processes modelled. The Cap version of downstream of the Keepit Dam. There is one the model has been reviewed as part of the end-of-system flow to the Namoi model at Cap auditing (Bewsher 2002a) and has been the Carroll Gap gauge (419006). accredited for Cap implementation. The Namoi model covers the catchments of The water sharing plan version of the model the Manilla River from its headwater inflows does not include water buybacks by the into Split Rock Dam to the confluence with Commonwealth and NSW governments the Namoi River, and the catchments of since the start of the water sharing plan. the Namoi River from the North Cuerindi 4.7.2 Results and discussion gauge (419005) to the lower flood plains of Namoi valley covered by Pian Creek and The water balances for without-development Namoi River and their anabranches. The and baseline conditions for the Gwydir Namoi River meets the Barwon River near system are summarised in Table 7. Walgett gauge (419057). There are two end- The Gwydir system has a good network of of-system flows, taken as inflows into the gauges on the contributing tributaries and Barwon–Darling model, at the Waminda as a consequence, 76% of the river system gauge (419049) in the Pian Creek and the inflows are based on gauged data and only Goangra gauge (419026) in the Namoi River. 24% are estimated using models. The total The flows from Mooki River are included as inflows in the Gwydir system are 996 GL/y. inflows at Breeza gauge (419027) and flows Under without-development conditions, 37% from Cox’s Creek are included at Boggabri of total inflows reaches the Barwon–Darling gauge (419032) in the model. system. This has decreased to 17% under The development of the Namoi and Peel baseline conditions, with 32% of inflows Cap models is described in detail in DIPNR being diverted. (2004d) and DNR (2006c). These models were reviewed as part of the Cap auditing and are accredited for Cap implementation (Bewsher 2005 and 2009). The models used for estimating baseline diversion limits are the water sharing plan version of models for the Namoi and Peel systems. There is no separate

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 21 AND BASELINE CONDITIONS Murray–Darling Basin Authority

documentation of the water sharing plan Table 8. The system has a limited number version of the model, but environmental of gauges on the contributing tributaries flow rules and water sharing arrangements and as a consequence only 38% of the in the model correspond to the Namoi river system inflows are based on gauged Water Sharing Plan (DIPNR 2004g) and the data. The remaining 62% of inflows are Peel River Water Sharing Plan (DECCW estimated using models. The total inflows 2010). The model does not include water are 1,883 GL/y. Under without-development buybacks by the Commonwealth and NSW conditions, the proportion of total inflows governments since start of the water that reaches the Barwon–Darling system sharing plan. is 44%. This has decreased to 35% under baseline conditions, with 14% of inflows 4.8.2 Results and discussion being diverted. The water balances for without-development and baseline conditions for the Namoi and Peel system are summarised in

Table 8 Water balances for the Namoi and Peel system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage - -4.7 Inflows Directly gauged 723.9 723.9 Indirectly gauged 1,151.8 1,153.3 Groundwater gain 7.5 9.1 Total inflows 1,883.1 1,886.3 Diversions Total modelled watercourse diversions - 265.2 Losses River groundwater loss 0.9 6.7 Storage evaporation losses 0.8 51.5 River evaporation losses 18.2 18.2 River losses 1,124.5 972.9 Effluent losses 209.5 319.9 Effluent return flows -209.5 -319.9 Irrigation drainage returns flows - 8.2 Losses in supplying Tamworth TWS - 0.3 Total losses 1,144.4 1,041.4 Outflows End–of-system outflows to Barwon–Darling model 828.3 652.5 Total modelled outflows 739.8 584.8 Unattributed flux Unattributed flux -1.1 -0.4

22 4.9 Macquarie–Castlereagh and The water sharing plan versions of the Bogan rivers models for Macquarie, Bogan, Marra, Marthaguy and Castlereagh were linked 4.9.1 Model description for the MDBSY project and this linked version of the model has been used for the The Macquarie–Castlereagh and Bogan Basin Plan modelling. There is no separate region is located in central-west NSW, documentation of the water sharing plan covers 6.9% of the area of the Basin and version of the model, but environmental flow has 9% of the total population of the Basin rules and water sharing arrangements in (CSIRO 2008h). The region comprises the model correspond to the water sharing the Castlereagh, Macquarie and Bogan plans for the Macquarie and Cudegong river basins. Rivers (DIPNR 2004b) and Castlereagh River For regulated parts of the Macquarie (DIPNR, 2004c). The model does not include River and for unregulated parts of the water buybacks by Commonwealth and NSW Castlereagh River, a daily time step IQQM government since the start of the water model has been developed by NOW. The sharing plan. Castlereagh River is modelled from inflows at Mendooran gauge (420004) to Coonamble 4.9.2 Results and discussion gauge (420005). The model covers the The water balances for without-development Macquarie River from the headwater inflows and baseline conditions for the Macquarie– into Chifley Dam to its confluence with the Castlereagh and Bogan system are Barwon River and the Cudgegong River from summarised in Table 9. the headwater inflows into Windamere Dam to its confluence with the Macquarie River at The system has a limited number of Burrendong Dam. Towards the lower end of gauges on the contributing tributaries and valley, the model covers the Bogan River and as a consequence only 39% of the river the floodplain areas between the Macquarie system inflows are based on gauged data. River and the Bogan River. The remaining 61% of inflows are estimated using models. The total inflows in the In the IRSMF modelling framework, flows at Macquarie–Castlereagh and Bogan system the following five gauging stations from the are 2,859 GL/y. The proportion of inflows Macquarie-Castlereagh model are used as that reaches the Barwon–Darling system inflows to the Barwon–Darling Model: under without-development conditions • Castlereagh River at the Coonamble is 27%. This has decreased to 22% under gauge (420005); baseline conditions, with 14% of total inflows • Marthaguy Creek at the Carinda gauge being diverted. (421011); • Macquarie River at the Carinda gauge (421012); • Bogan River at the Gongolgon gauge (421023); and • Marra Creek at the Billybingbone Bridge gauge (421107).

The development of the Macquarie River Cap model is described in detail in DNR (2006b). This model was reviewed as part of the Cap auditing and is accredited for Cap implementation (Bewsher 2011a). WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 23 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Table 9 Water balances for the Macquarie–Castlereagh and Bogan River system for without‑development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage - -4.3 Inflows Directly gauged 1,104.7 1,104.7 Indirectly gauged 1,754.4 1,523.3 Total inflows 2,859.1 2,628.0 Diversions Total modelled water course diversions - 380.3 Losses On-farm evaporation - 5.0 River losses 1,576.8 1,280.9 Net evaporation from storages - 54.0 Return flows 928.2 688.3 Macquarie Marshes evaporation 328.0 228.8 River evaporation 16.5 16.7 Effluent losses 939.3 693.0 Total Losses 1,932.4 1,585.1 Outflows End-of-system outflows to Barwon–Darling model 760.0 576.9 Total modelled outflows 926.7 667.3 Unattributed flux Unattributed flux 0.0 -0.3 4.10 Barwon–Darling models in the reach of the Barwon River between the Mungindi and Walgett gauges, 4.10.1 Model description and from the Warrego, Condamine–Balonne and Macquarie–Castlereagh models in The Barwon–Darling region is located the reach between the Walgett and Louth in north-western NSW and covers 13% gauges. The lower end of the model covers of the Basin. The region has 2.5% of the the wetlands, lakes and billabongs of the Basin’s population. The region contains Talyawalka wetland system. the Talyawalka wetland system, which is a nationally important wetland located The Barwon–Darling is an unregulated between Wilcannia and Menindee on the system and in-stream minimum flows Darling Riverine Plains (CSIRO 2008a). are ensured by specifying various flow For development of management policies thresholds for water users with different and for general regulation of flows, a daily licence classes. There are three irrigation time step IQQM model was developed by license classes, i.e. classes A, B and C. NOW. The model receives tributary inflows There are issues with underestimation of from the Gwydir, Namoi and Border–Rivers inflows from the tributary models during

24 some of the major floods. Therefore, entitlements and continuous carryover). estimates of additional flows, which may The development of this model is described bypass the most downstream gauges of the in detail in DNR (2006a). The model tributary catchments, are included in the does not include water buybacks by Barwon–Darling model. Commonwealth/NSW Governments from the system. The model is yet to be audited The model used for Basin Plan development for accreditation for setting the Cap and for is at the 2007/08 level of irrigation development and incorporates the Cap annual Cap compliance. As a consequence accounting rules of July 2007 (i.e. reduced of this audit and its recommendations, the diversion estimate may be revised.

Table 10 Water balances for the Barwon–Darling system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage - - Inflows Warrego 69.4 58.2 Condamine–Balonne 569.4 241.8 Moonie 96.3 71.4 Border Rivers 797.4 512.6 Gwydir 367.5 173.9 Namoi 828.3 652.5 Macquarie–Castlereagh 760.0 576.9 Local Barwon–Darling inflows 913.9 483.2 Total inflows 4,402.3 2,770.6 Diversions Total modelled watercourse diversions - 197.5 Losses Evaporation losses from storages Warrego 32.3 28.2 Floodplain lakes 79.7 50.1 River evaporation 49.5 48.5 Sub-total storage losses 161.5 126.8 River losses Reach losses 1,072.5 678.4 Effluent losses 75.5 43.3 Sub-total river losses 1,148.0 721.8 Total losses 1,309.5 848.6 Outflows Menindee Lakes end-of-system flow 3,092.1 1,723.2 Unattributed flux Unattributed flux 0.7 1.3

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 25 AND BASELINE CONDITIONS Murray–Darling Basin Authority

4.10.2 Results and discussion its headwater inflows into Wyangala Dam and Belubula River inflows to the Carcoar The water balances for without-development Dam. The river breaks out into Willandra and baseline conditions for the Barwon– Creek and eventually runs dry. The model Darling system are summarised in Table ends at the Great Cumbung Swamp and has 10. The Barwon–Darling system gets contributions from various tributaries, which no contribution to any of the downstream have a gauging station near their confluence systems. The model includes key water with the Barwon–Darling system. However, regulation storages (i.e. Wyangala Dam, during flood events significant volumes of Carcoar Dam, Lake Cargelligo, Brewster water can bypass these gauges and are then Weir and Lake Brewster). only measured at the gauging stations on The development of the Lachlan Cap model the Barwon–Darling system. The volume of is described in DLWC (2002). The model water that bypasses these tributary gauges has been reviewed as part of the Cap can comprise a significant proportion of auditing and has been accredited for Cap total Barwon–Darling inflows during high implementation (Bewsher 2002b). flow periods. This has been accounted for The models used for estimating baseline in the water balance as local inflows to the diversion limits are the water sharing plan Barwon–Darling system. The total inflows to the Barwon–Darling system are estimated version of model. There is no separate to be 4,402 GL/y under without-development documentation of the water sharing plan conditions. Under without-development version of the model, but environmental conditions, 70% of the total inflows reach the flow, irrigation demands and environmental Menindee Lakes. Under baseline conditions flow rules in the model correspond to the inflows have decreased to 37% of the Lachlan Water Sharing Plan (DIPNR without-development inflows. The baseline 2004e). The model does not include water inflows into the Barwon–Darling system are buybacks by the Commonwealth and NSW affected by developments in all upstream governments since the start of the water river valleys; therefore, reductions in sharing plan. end-of-system flows are due to the combined effect of upstream valley 4.11.2 Results and discussion developments and developments in the The water balances for without- Barwon–Darling system itself. development and baseline conditions for Under baseline conditions, diversions in the Lachlan system are summarised in the Barwon–Darling system are 7% of Table 11. The Lachlan system has a good its inflows. network of gauges on the contributing tributaries and as a consequence 70% 4.11 Lachlan of the river system inflows are based on gauged data and 30% are estimated using 4.11.1 Model description models. The total inflows into the Lachlan system are 1,424 GL/y. The Lachlan is an The Lachlan region is situated in central isolated system; most of the time water western New South Wales. It covers 8% of ends in wetlands and billabongs with no the total area of the Murray–Darling Basin contribution to the Barwon–Darling or the and has 4.7% of the population of the Basin River Murray system. (CSIRO 2008f). Under the historical climate scenario, The Lachlan is modelled with a daily diversions are 20% of system inflows. timestep IQQM model (Hameed and Podger 2001). The Lachlan River is modelled from

26 Table 11 Water balances for the Lachlan system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage - -8.8 Inflows Directly gauged 991.8 991.8 Indirectly gauged 432.4 432.4 Total inflows 1,424.3 1,424.3 Diversions Total modelled water course diversions - 286.6 Losses Wetland replenishment - 26.2 Environmental contingency flow - 5.0 River groundwater loss - 17.4 Evaporation from public storages - 67.7 Evaporation from natural water bodies 170.3 84.0 River loss and effluent loss 1,253.9 946.5 Total losses 1,424.3 1,146.8 Outflows End-of-system outflows - - Unattributed flux Unattributed flux -0.0 0.4 4.12 Murrumbidgee Tantangara Storage to Burrinjuck Dam; and the Murrumbidgee model (BIDG) which 4.12.1 Model description represents the main river from Burrinjuck and Blowering Dams to the ends-of-system The Murrumbidgee region is located in at Balranald, Billabong Creek at Darlot and southern NSW and covers 8.2% of the Forest Creek. Flows from the Cotter and Basin. The region is home to 27% of the Googong storages were provided by ACTEW total population of the Basin (CSIRO to represent usage in the ACT. This includes 2008l). It includes the nationally significant the Murrumbidgee to Googong transfer, an mid-Murrumbidgee wetlands and low enlarged Cotter Dam and a projected ACT Murrumbidgee floodplain, as well as the population of 396,000. ACT diversions have extensive Murrumbidgee and Colleambally been included as 40 GL/y, equal to the Cap. irrigation areas. The Cap version of the Murrumbidgee model The Murrumbidgee modelling suite (BIDG) is described in DWE 2007. The model is comprised of three models: the has been reviewed as part of the Cap Snowy scheme (SNAT under without- auditing and has been accredited for Cap development conditions, SNOW otherwise); implementation (Bewsher 2010b). the upper Murrumbidgee model (UBID) which represents the catchment from

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 27 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Table 12 Murrumbidgee Water for Rivers purchases Murrumbidgee Water for Rivers purchases Entitlement (GL) LTCE (GL/y) Infrastructure Forest Creek stage 2 23.4 22.2 Forest Creek stage 1 — alternative stock and 11.3 10.7 domestic supply Barren Box Swamp water recovery* 20.0 19.3 Total 54.7 52.2 Market purchase and infrastructure programs which would lead to reduction in diversions from river NSW regulated general security market water 40.4 25.7 purchase On-farm reconfiguration 21.5 13.7 Colleambally Irrigation Co-Op Ltd 3.5 3.4 Hay Private Irrigation District stock and domestic 1.0 1.0 pipeline Total 66.4 43.8 Sum of infrastructure and market purchases 121.1 96.0 * This has been incorrectly included in the infrastructure category, but should be part of infrastructure programs that lead to reduction in diversions from the river and thus the baseline diversion limit should be reduced by this amount.

Table 13 Murrumbidgee TLM purchases • The baseline Murrumbidgee model was linked to the upper Murrumbidgee and Entitlement LTCE Snowy scheme models to get better The Living Murray (GL) (GL/y) representation of the ACT and Snowy Infrastructure 3.5 2.2 scheme impacts on the Burrinjuck Dam Market purchase 78.4 49.9 and Blowering Dam inflows. TOTAL 81.9 52.1 • The model has been extended to include the Jounama catchment upstream of Basin Plan modelling for the Murrumbidgee Blowering Dam. system is based on the water sharing • The without-development model is also plan (DIPNR 2004f; DWE 2009) version of a new model as compared to the version the model and Snowy inflows are based used by CSIRO for the MDBSY project on the pre-corporatisation version of the and was developed by the NOW, based Snowy model. There is no documentation on the baseline model. available for the water sharing plan version of the model as provided to MDBA. This • Water recovery for TLM (purchase of original model version does not include 78.4 GL of entitlement) was added to water recovery for TLM, RiverBank or the baseline model by MDBA. Water Water for Rivers for the Snowy Scheme, recovery under the Water for Rivers or water recovered by the Commonwealth program is not in the model, but Environmental Water Holder (CEWH). model results have been corrected for this recovery externally to determine The changes carried out to the baseline diversion limits. Table 12 and Murrumbidgee model as compared to the Table 13 detail TLM and Water for Rivers water sharing plan version before its usage purchases to date. for determining baseline diversion limits were as follows. 28 Table 14 Water balances for the Murrumbidgee system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage - -16.8 Inflows Directly gauged 3,610.4 4,074.4 Indirectly gauged 625.8 625.8 Transfer from Murray through Finlay’s Escape - 42.1 Total inflows 4,236.3 4,742.3 Diversions Net modelled water course diversions - 2,001.5 Losses Net evaporation from NSW storages - 31.7 Small on-river wetlands - 0.1 Lowbidgee evaporation total 310.6 213.7 River losses 960.2 773.9 Total losses 1,270.7 1,019.4 Outflows Billabong Creek at Darlot (to Murray, via Edward R.) 123.5 320.7 Murrumbidgee River at Balranald (to Murray) 2,724.2 1,224.6 Forest Creek (to floodplain) 29.9 56.8 TLM supply to Murray 34.3 Total outflows 2,877.5 1,636.4 Unattributed flux Unattributed flux* 88.0 101.8 * Includes river reach evaporation and change in reach storage.

• The Balranald end-of-system flow 4.12.2 Results and discussion demand was updated to include the water The water balances for without- sharing plan minimum flow rule which development and baseline conditions for has come in effect from 2008–2009. the Murrumbidgee system are summarised • Inputs from the Murray system which in Table 14. The system has a reasonable affect the Murrumbidgee system number of gauges on the contributing (Finlay’s Escape, Lake Victoria storage tributaries, and as a consequence 85% levels and Murray announced allocations of the river system inflows are based on for Lowbidgee diversion determination) gauged data, and only 15% are estimated were updated based on the most using models. The total inflows to the recent information produced by the Murrumbidgee system excluding the Snowy Murray model. (for without-development conditions) are 4,236 GL/y. The total inflows are higher under baseline conditions (4,742 GL/y)

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 29 AND BASELINE CONDITIONS Murray–Darling Basin Authority

due to the transfer from the Snowy River slopes of Mount Hotham and Mount Buffalo (included in the directly gauged inflows), through the Ovens valley, passing numerous inter-valley transfers and the impact of regional towns. The system is modelled ACT diversions. to the confluence with the Murray River For the Murrumbidgee, 67% of its upstream of Yarrawonga Weir. The most total inflows would reach the Murray downstream gauge on the Ovens River is system (Balranald plus Darlot) under at Peechelba (403241). The Ovens model without-development conditions and this was developed in 1995 and there have been has decreased to 33% under baseline various reviews and updates since then. conditions. The total diversions are 42% The most recent review and recalibration is of baseline inflows. described in SKM (2008). The Ovens model was received from the Victorian Department 4.13 Ovens of Sustainability and Environment (DSE). The model inputs were last updated to 4.13.1 Model description December 2008 by SKM (2009b). The Ovens region is in north-eastern The REALM model of the Ovens River Victoria. It covers 0.7% of the total area of represents the current level of development the Murray–Darling Basin and has 2.3% and water sharing rules as of 2009. of the total population in the Basin (CSIRO The water sharing rules are documented 2008m). The Ovens system is modelled in the relevant bulk entitlements for the with a weekly REALM model that covers Ovens River (DSE 2010). The model has only the entire Ovens River from the northern been updated to December 2008, and does

Table 15 Water balances for the Ovens system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage 0.0 0.1 Inflows Directly gauged 1319 1,319.0 Indirectly gauged 434.0 434 Total inflows 1,753 1,753 Diversions Total modelled water course diversions - 25.4 Losses Net evaporation - 1.5 Farm dam impact - 14.0 River losses 17.6 19.4 Total losses 17.6 34.9 Outflows End of system flows (Peechelba) 1,735.2 1,692.9 Unattributed flux Unattributed flux 0.0 0.0 Water balance is for period from July 1895 to December 2010.

30 therefore not cover the January 2009 to June 4.14 Goulburn–Broken, Campaspe 2009 period. The Ovens flows to the Murray and Loddon rivers system for this period are based on actual (Peechelba flow) data. 4.14.1 Model description The version of the model used in this project The Goulburn–Broken, Campaspe and explicitly includes small catchment dams Loddon regions are situated in northern (farm dams) and the effects of groundwater Victoria. The regions cover 4.8% of the area pumping. Groundwater pumping is of the Murray–Darling Basin (including the only modelled in the upper Ovens River Avoca region) and have 16% of the Basin’s catchment in an area with a direct hydraulic population (CSIRO 2008d; 2008b; 2008g). connection to the river. Other groundwater The Goulburn–Broken, Campaspe and impacts, which under most flow conditions Loddon river systems are modelled together are small relative to streamflow volumes, in the monthly ‘Goulburn Simulation Model’ are not explicitly modelled. (GSM), because they are hydrologically linked. The Broken River flows into the 4.13.2 Results and discussion Goulburn River near Shepparton, and the The water balances for without-development Goulburn, Campaspe and Loddon rivers and baseline conditions for the Ovens are all linked via the Waranga Western system are summarised in Table 15. As Channel (WWC), which transfers water mentioned above, the model has been from the Goulburn River to the Campaspe updated to December 2008 and does not and Loddon river catchments. The WWC cover the whole Basin Plan baseline period continues on from the Loddon River (i.e. up to June 2009). Hence, the water catchment through to the Wimmera region. balances provided present annual average The GSM includes outflows from Casey’s figures for the period from July 1895 to Weir to Broken Creek, but does not model December 2008. Broken Creek. Due to the links between the three different river systems, changes The inflows to the Ovens model are in one part of the GSM can affect flows determined using a range of different and reliability of supply in other GSM methods, including gauged tributary river systems. flows that may be factored in to account for the ungauged part of the tributary The baseline model being used represents catchment downstream of the gauge, the level of development and water sharing as well as water balance methods and rules as of 2009 with diversions at Cap level rainfall–runoff modelling (SKM 2009b). less water recoveries for TLM and Water The Ovens catchment has a relatively high for Rivers, as well as Victorian government number of gauges and 75% of the inflows water recovery in the Loddon catchment. The water sharing rules are documented have been identified as directly gauged. in the relevant bulk entitlements for the The total inflows into the Ovens system Goulburn, Broken, Campaspe and Loddon are 1,753 GL/y. For the Ovens system, 99% rivers (DSE 2010). The model was provided of inflows would reach the Murray system by the DSE. The configuration of the GSM under without-development conditions, as model and its calibration and validation is only 1% of inflows is lost. Under baseline described in the Cap report (DSE 2005). conditions, 97% of inflows still flow into the This model was audited and accredited Murray, which highlights a relatively low for use for annual Cap auditing (Bewsher level of development in the catchment; only 2006). The last major model configuration is 1.4% of inflows are diverted under baseline described in DSE (2007). conditions and historical climate.

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 31 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Table 16 Environmental water recovery and trade entitlements included in the GSM baseline model Description HRWS (GL) LRWS (GL) Total (GL) Goulburn–Broken Water recovery for TLM Living Murray account reconfiguration 19.2 19.2 Shepparton modernisation(1) 26.0 9.4 35.5 Purchase 5.6 5.6 20% sales water 141.2 141.2 Water for Rivers water recovery Normanville 3.9 3.9 IMSVID 10.9 10.9 Strategic Measurement project 0.5 0.5 Water share purchases (incl. Madowla Park) 4.2 17.9 22.1 Inter-valley trade Permanent trade 110.2 110.2 Campaspe Water recovery for TLM Account reconfiguration 0.1 0.1 20% of sales water 5.0 5.0 Inter-valley trade Exchange rate trade until June 2007 1.2 1.2 Loddon Victorian government water recovery Boort Wetlands 2.0 2.0 20% of sales water 2.0 2.0 (1) These numbers represent TLM entitlements as included in the model at the time the Basin Plan scenarios were run. However, these numbers do not exactly represent the TLM entitlements resulting from the Shepparton modernisation and will be corrected in the model to 20.5 GL HRWS and 15.8 GL LRWS for future scenarios.

Water recovery and inter-valley trade deliver up to 75 GL/y from the Goulburn included in the model has been summarised River downstream of Lake Eildon to in Table 16. Some other key features of the Melbourne; this is also excluded from model are as follows. the model. • It includes Winton Swamp (27 GL • It excludes the proposed capacity), which was previously the site decommissioning of irrigation of Lake Mokoan (365 GL capacity) and supplies to the Campaspe Irrigation has now been decommissioned. District (19.5 GL HRWS and 10.2 GL • It excludes the 225 GL/y of water LRWS entitlement). savings and infrastructure changes • It excludes the connection of the town under the Northern Victoria Irrigation of Axedale to the Bendigo water supply Renewal Project (NVIRP). Part of system. The town is assumed to source NVIRP is the Sugarloaf Interconnector its 0.1 GL/y from the Campaspe River. pipeline to Melbourne, which will

32 • It excludes the Goldfields Superpipe, The inflows to the various river reaches which supplies water to Ballarat (up to have been estimated using various methods 18 GL/y) and Bendigo (up to 20 GL/y). including ‘gauged and transposed flows’ The pipe runs from the WWC near (in which gauged tributary flows are factored Colbinabbin to Sandhurst Reservoir up to include an estimate of the ungauged in the Bendigo urban system, then to part of the tributary catchment below the White Swan Reservoir in the upper gauges) and water balance methods based reaches of the Barwon River basin in on main stream gauges (SKM 2009a). southern Victoria. The total inflows in the Goulburn–Broken system under historical climate are 3,378 4.14.2 Results and discussion GL/y. For the Goulburn–Broken system it is estimated that 99.7% of its total The results for the Goulburn–Broken, inflows would reach the Murray system Campaspe and Loddon River systems under without-development conditions, are discussed separately in the which has been decreased to 49% under following sections. baseline conditions, with 46% of inflows being diverted. Goulburn–Broken The negligible losses being predicted by The water balances for without-development the without-development conditions model and baseline conditions for the Goulburn– are because the model does not include an Broken system are summarised in Table 17. estimate of river losses along the Goulburn

Table 17 Water balances for the Goulburn–Broken system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage -0.0 -20.5 Inflows Total inflows 3,377.6 3,383.6 Diversions Broken diversions - 13.2 Goulburn diversions - 1,551.6 Total modelled water course diversions - 1,564.8 Losses Irrigation drainage returns - -29.1 River losses 2.6 168.3 Net evaporation 7.1 31.4 Total losses 9.7 170.5 Outflows End-of-system flow at McCoys Bridge (to Murray model) 3,368.0 1,665.8 Total modelled outflows 3,368.0 1,667.7 Unattributed flux Unattributed flux 0.0 1.1

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 33 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Table 18 Water balances for the Campaspe system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage 0.0 -2.5 Inflows Total inflows 289.7 289.7 Diversions Total modelled water course diversions - 110.9 Losses Net evaporation - 16.8 Channel losses 8.9 10.5 Total losses 8.9 27.3 Outflows End of system flow at Rochester (to Murray model) 280.8 156.8 Total modelled outflows 280.8 154.0 Unattributed flux Unattributed flux 0.0 0.1

Table 19 Water balances for the Loddon system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage 0.0 -1.3 Inflows Total inflows 255.4 255.4 Diversions Total consumptive diversions - 88.6 Environmental diversions (Boort wetlands) - 2.2 Total modelled water course diversions - 90.7 Losses Net evaporation - 14.4 Channel losses 16.9 22.2 Total losses 16.9 36.5 Outflows End-of-system flow at Appin South (to Murray model) 144.7 67.8 To flood breakouts u/s from Appin South 93.7 61.5 Total outflows 238.5 129.3 Unattributed flux Unattributed flux 0.0 0.1

34 River; the river losses reported in the water Murray system under without-development balances for the without-development conditions. Under baseline conditions this scenario are only for the Broken system. has decreased to 51%, with 35% of inflows The baseline model only includes an being diverted for consumptive use. estimate of additional river losses along the upper Goulburn that occur due to river 4.15 Wimmera operations. The floodplain losses in the model are included in estimates of flow 4.15.2 Model description contribution from catchments downstream The Wimmera region is located in western of Eildon and partly in the losses between Victoria. It covers 3% of the total area of McCoys Bridge and River Murray reach the Basin and has 2.5% of the Basin’s between Yarrawonga and Torrumbarry. population (CSIRO 2007e). The estimation of losses and flows from tributaries downstream of Eildon in the The Wimmera model is a monthly REALM Goulburn model needs to be reviewed to representation of the Wimmera River. The better represent flow contribution vis-a-vis baseline model also includes the Glenelg floodplain losses. River to downstream of Rocklands Reservoir and the Avon–Richardson rivers. These Campaspe rivers interact with the Wimmera headworks system, so that transfers can be made from The water balances for without-development the Glenelg to the Wimmera. Surface water and baseline conditions for the Campaspe in the Wimmera River is not connected to system are summarised in Table 18. River the River Murray and hence there are no system inflows have been estimated downstream impacts on other reporting based on a range of different methods regions in the Murray–Darling Basin. (SKM 2009a), including the gauged and transposed flows (described for the The Cap version of the model has been Goulburn–Broken system above) and water described by W&D Engineering and Legal balance methods. The total inflows to the Services (W&D 2009). This model has been Campaspe system are currently 290 GL/y. audited and accredited for use for annual For the Campaspe system, it is estimated Cap auditing (Bewsher 2011b). The without- that 97% of total inflows would reach the development and baseline models used Murray system under without-development for basin planning have been provided by conditions. Under baseline conditions this the DSE. has decreased to 53%, with 38% of inflows The baseline model represents the level being diverted. of development and water sharing rules as of October 2010. The water sharing Loddon rules are documented in the relevant bulk The water balances for without-development entitlements for the Wimmera and Glenelg and baseline conditions for the Loddon rivers (DSE 2010). The model includes system are summarised in Table 19. The stages 1 to 7 of the northern Mallee pipeline inflows of the Loddon system are estimated and includes supply systems 1 to 6 (i.e. all based on regressions using nearby supply systems) of the Wimmera–Mallee tributary gauges and water balances using pipeline. The savings from these pipeline mainstream gauges (SKM 2009a). The projects have created new entitlements total inflows to the Loddon system are 255 for the environment and future growth GL/y. For the Loddon system it is estimated and use of these entitlements has been that 93% of total inflows would reach the activated in the model. There is 40.56 GL/y

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 35 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Table 20 Water balances for the Wimmera system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage -7.1 -7.9 Inflows Inflows 248.3 248.3 Inflows from Avon and Richardson Rivers1 - 22.6 Transfers from other basins (Glenelg) - 24.6 Total inflows 248.3 295.5 Diversions Total consumptive diversions - 65.7 Wetland diversions - 0.9 Total modelled diversions - 66.6 Losses Evaporation from lakes 180.6 146.6 Evaporation and loss from headwater storages and - 34.4 channels River losses 55.3 27.5 Flows to lakes and wetlands 19.3 28.4 Total losses 255.2 236.9 Outflows Total end-of-system outflows (to Murray) 0.0 0.0 Unattributed flux Unattributed flux 0.1 0.2 1 Not included in the without-development model of environmental water entitlement in the system are summarised in Table 20. model, which includes 32.2 GL/y from the The total inflows to the Wimmera system northern Mallee pipeline stages 1 to 7 under without-development conditions and 8.3 GL/y from the Wimmera–Mallee are 248 GL/y. However, under baseline pipeline supply systems stages 1 to 6. conditions, inflows are higher due to the The allocations to these entitlements are 24.6 GL/y transfer from the Glenelg River managed as a combined volume, which is and the inclusion of the Avon–Richardson shared between the Wimmera and Glenelg inflows. From the Wimmera system there systems. The model also includes supply are no outflows into the Murray system to the Horsham Irrigation District (19 GL/y and the system ends in terminal lakes, irrigation product and 9 GL/y irrigation including Lake Hindmarsh, Lake Albacutya loss entitlements). and a series of smaller lakes in the Mallee. The flows to these lakes and wetlands 4.15.2 Results and discussion have been included in the water balance as losses. Under baseline conditions, 23% of The water balances for without-development the baseline inflows are diverted. and baseline conditions for the Wimmera 36 4.16 Murray The model includes the four major storages: Dartmouth Dam on the Mitta Mitta River, 4.16.1 Model description Hume Dam on the Murray River, Menindee Lakes on the lower Darling and Lake The Murray region straddles southern New Victoria (an off-river storage connected to South Wales, northern Victoria and south- the Murray River). The Menindee Lakes eastern South Australia. It represents 19.5% system is modelled as four major lakes: of the total area of the Murray–Darling Wetherell, Pamamaroo, Menindee and Basin and has 16% of the Basin’s population Cawndilla. In addition, a number of weir (CSIRO 2008j). pools and natural wetlands and floodplains The Murray and lower Darling systems are included in the model. A number of are modelled using the Murray monthly smaller weirs are not included as they do simulation model (MSM) and a daily not impact on monthly operations (MDBC routing model (Bigmod). The modelling 2007). The model simulates: suite has been used for development and • water sharing arrangements between implementation of range of water resource the states, as per the Murray–Darling planning and management policies and Basin Agreement (Schedule 1 to the operating rules including Cap on water use, Water Act 2007 (Cwlth)) the basin salinity management strategy, development of optimal operating strategies • water accounting as per the for major storages, water accounting and Murray–Darling Basin Agreement resource assessment (MDBC 2002a; MDBC • allocation by states to groups of 2007; Bewsher 2008). water users The model commences with headwater • irrigation water demands in the key inflows from the Murray River (about 40 km regions throughout the system south of Mt. Kosciuszko) and Darling River • transfers required between storages to inflows into Menindee Lakes, and finishes ensure that demand can be met at the barrages which separate the Lower • operation of various dams and Lakes from the sea (MDBC 2002b). More structures including orders to meet recently, a hydraulic model of hydrodynamic forecast demand and pre-releases from behaviours and salinity in the Coorong each storage for flood mitigation. developed by the CSIRO (Webster 2007) has been included in this modelling suite. The baseline conditions of the Murray and lower Darling system that have been used The model receives inflows from the Snowy are as follows. Mountain Hydro-electric Scheme (SMHS) via releases through the Murray 1 Power • They are based on the water sharing and Station (WAMC 2002). It also receives inflows management arrangements in place at from a number of tributaries including: June 2009, i.e. the water sharing plan for NSW Murray and lower Darling systems • Kiewa River at Bandiana and Cap conditions for Victoria and • Ovens River at Peechelba SA with adjustment for water recovery • Goulburn River at McCoy’s Bridge under TLM and the Water for Rivers • Campaspe River at Rochester program (MDBA 2011). • Loddon River at Appin South • Water trade within the model includes • Billabong Creek at Darlot permanent entitlement trade to June 2009. This level of trade is used for the • Murrumbidgee River at Balranald entire modelling period. This includes • Barwon–Darling rivers at the increases or decreases in the NSW, Menindee Lakes

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 37 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Victorian and SA Cap as result of such model maintains these accounts using permanent trade. The model also the announced allocation level of the includes the ability for Tandou to trade tributary models and calls water out up to 20 GL when required and when from the accounts when it is needed. Menindee Lakes is in MDBA control. For ensuring deliverability of the TLM Apart from this, however, no inter-valley water that the Murray can call out, a temporary trade is modelled. time series describing the available • Environmental flow provisions included channel capacity in the Goulburn system in the baseline model include: is used to limit the maximum TLM water that can be called out. –– additional dilution flows of 3,000 ML/d, if the volume of water stored • TLM works and measures include and in Menindee Lakes is more than are operated as: 1,650 GL in June and July, 1,500 GL –– rostered environmental watering in August and 1,300 GL in any other requirements based on pre-defined months, and the combined storage rules for achieving or maintaining of the Hume and Dartmouth dams is ecological health conditions at TLM more than 2,000 GL icon sites –– Darling Anabranch environmental –– scheduled water delivery from the releases during periods of off- identified watering requirements allocation on the Lower Darling within available TLM and River –– environmental water allocation of up Murray Increased Flows (RMIF) to 150 GL/y for the Barmah–Millewa water on a most-needed basis. Forest, and the associated watering • SA restriction policy and carryover rules (MDBC 2006a, 2006b). provisions are included (MDBA 2009). –– a 500 GL long-term Cap equivalent (LTCE) water recovery for TLM 4.16.2 Results and discussion initiative and environmental water delivery of the recovered water The water balances for without-development (Table 21) and baseline conditions for the Murray and Lower Darling system are summarised in –– recovery of water for Water for Rivers Table 23. The Murray and Lower Darling (Table 22) and 70 GL River Murray system is well gauged and only a small increased flow from Snowy scheme. fraction (<2%) of its inflows are estimated. • Calling available water from tributary The total inflows into the Murray and TLM accounts is managed in the Murray Lower Darling system under without- model on an as need basis. To do this, development conditions are 16,386 GL/y. when end-of-system flows at tributaries The total inflows under baseline conditions are transferred to the Murray model have been reduced due to developments and used as inputs to the Murray in its contributing catchments and are model, the end-of-system flows are 12,368 GL/y under historical climate. reduced by the volume released from Under without-development conditions, their TLM accounts. This is because 76% of the total Murray and Lower Darling the release determined by the tributary inflows reach the sea through the Murray models (Goulburn simulation model Mouth. Under baseline conditions this and Murrumbidgee model) may not be has decreased to 42% of current inflows, useful for meeting environmental water which corresponds to only 31% of the needs in Murray. Instead, the Murray without-development inflows.

38 Table 21 The Living Murray water recovery projects

LTCE Entitlement Proponent Project (GL) (GL) Category of entitlement NSW Murray Murray Irrigation Limited 17.8 100.0 supplementary water NSW Murray general Pipe It 0.1 0.2 security water NSW Murray general 69.2 security water NSW Murray high 1.1 security water Lower Darling high Market purchase measure 115.3 0.5 security water Lower Darling 150.0 supplementary water Murrumbidgee general 76.8 security water NSW Lower Darling Tandou Limited 9.3 100.0 supplementary water Lower Darling general 47.0 47.8 security water Poon Boon Lakes 9.0 - (modelled) NSW Package B NSW Murray high 3.7 security water 7.1 Vic Murray high reliability 3.7 water share NSW Murray high 0.3 Wetland Water Recovery – 0.6 security water stage 1 Vic Murray high reliability 0.3 water share ...continued

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 39 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Table 21 The Living Murray water recovery projects

LTCE Entitlement Proponent Project (GL) (GL) Category of entitlement Vic Murray low reliability 98.8 water share Goulburn low reliability 141.2 water share Sales unbundling 120.0 Campaspe low reliability 5.1 water share Vic Murray low reliability 3.0 water share1 Vic Murray high reliability 5.7 Vic water share Victorian reconfiguration 24.9 Vic tributaries high 19.2 reliability water share Vic tributaries high 20.5 reliability water share Shepparton modernisation 29.3 Vic tributaries low 15.8 reliability water share Lake Mokoan decommissioning and Snowy high 28.1 - Modelled reliability water share 22 GL 18.9 SA government held water 12.3 South Australian River SA 35.0 Purchase from willing 4.3 Murray sellers 1.1 Australian NSW Murray general Water efficiency tender 0.2 0.2 Government security water

1 Not included in the model ...continued

40 Table 21 The Living Murray water recovery projects

LTCE Entitlement Proponent Project (GL) (GL) Category of entitlement South Australian River 7.3 Murray Living Murray water Vic Murray high reliability 18.6 7.2 purchase water share Vic tributaries high 5.5 reliability water share Vic Murray high reliability 1.9 water share Vic tributaries high 0.02 reliability water share Pilot market purchase 13.3 NSW Murray general MDBA 13.0 security water Murrumbidgee general 1.6 security water NSW Murray general 0.9 1.3 Ricegrowers’ on-farm water security water Efficiency round 1 Murrumbidgee general 0.1 0.2 security water NSW Murray general 4.2 5.2 Ricegrowers’ on-farm water security water Efficiency round 2 Murrumbidgee general 1.0 1.2 security water Sustainable Soils Vic Murray high reliability and Farms on-farm 3.0 3.2 water share reconfiguration

Table 22 Water for Rivers recovery in the Murray Valley Project Entitlement (GL) Market purchase (GS) 29.955 NSW Murray Deniliquin Golf Club (GS) 0.238 Edward Gulpa wetland evaporation savings 7.0 Woorinen stock and domestic pipeline (HRWS) 1.5 IMSVID excluding Normanville and Woorinen (HRWS) 5.488 Market purchase (HRWS) 5.419 VIC Murray Market purchase (LRWS) 5.08 North-east CMA surrender of water share (HRWS) 0.706 Madowla Park reconfiguration (HRWS) 1.99 On-farm reconfiguration (LRWS) 0.46

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 41 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Table 23 Water balances for the Murray system for without-development and baseline scenarios Without- Water balance (GL/y) development Baseline Storage Total change in storage -13.0 -75.4 Inflows Darling (inflow to Menindee Lakes) 3,092.1 1,723.2 Murrumbidgee (Balranald) 2,724.2 1,257.0 Murrumbidgee (Darlot) 123.5 320.7 Catchment managed by Snowy scheme 616.9 1,132.8 Ovens at Peechelba 1,728.2 1,686.0 Goulburn at McCoy’s Bridge 3,368.0 1,665.2 Campaspe at Rochester 280.8 151.9 Loddon at Appin South 144.7 67.8 Directly gauged Murray sub-catchments 4,047.1 4,035.9 Indirectly gauged Murray sub-catchments 260.2 327.6 Total inflows 16,385.6 12,368.1 Diversions NSW Murray diversions - 1,680.2 NSW lower Darling diversions - 54.7 Victorian Murray diversions - 1,657.0 SA Murray diversions - 665.0 Total diversions - 4,056.3 Losses Total net evaporation 427.6 611.6 Net groundwater loss - 47.0 Total loss including SA 3,593.9 2,585.4 Total losses 4,021.4 3,244.0 Outflows Barrage outflow 12,377.2 5,142.4 Unattributed flux Unattributed flux 0.00 0.02

42 Under baseline conditions, diversions are 6 ACCOUNTING FOR 25% of the without-development inflows (or 33% of baseline inflows). The total end-of- UNMODELLED INFLOWS system flows are 5,142 GL/y. AND DIVERSIONS FOR PREPARATION OF THE 5 UNMODELLED PROPOSED BASIN PLAN DIVERSIONS The without-development and baseline In a number of SDL resource units there are model scenarios, as presented above, have some diversions which are not modelled by been used to make estimates of total inflows the river systems models. These could be and Baseline Diversion Limits (BDLs) diversions from the catchments upstream presented in the proposed Basin Plan. of storages or from catchments upstream However, the figures presented in Schedule of inflow points to these models. In most 1 to the proposed Basin Plan may differ cases these diversions have been estimated from figures presented in the water balance by state agencies as part of reporting for the tables for individual valleys, as various Cap. The unmodelled diversions in various post-processing steps have been applied valleys since the introduction of the Cap are to account for inflows and diversions not summarised in Table 24. These diversions included in the models. from unregulated watercourses have been The total inflows estimate provided in estimated based on crop area surveys Schedule 1 to the proposed Basin Plan are and assessed irrigation requirements in based on the local inflows (i.e. excluding NSW (MDBA 2009) and percent adjustment inflows from upstream modelled connected of the modelled component in Victoria river systems), modelled for without- (Bewsher 2006). development conditions. However, these The unmodelled diversions included in modelled inflows do not include explicit the total watercourse diversions are the representation of interceptions (e.g. farm average of reported unmodelled diversions dams and plantation forestry) or some for the period 1997/98 to 2009/10 for NSW unregulated watercourse diversions (see and Victoria. Section 5 of this document). The interception by farm dams and forestry plantations are based on the most recent available estimates of the impact of these interception activities on runoff. Outcomes from studies undertaken by SKM, CSIRO and the Bureau of Rural Sciences (2010) and SKM (2007) have been used for these estimates. However, these studies acknowledge limitations to the accuracy of their results, and MDBA recognises that their application to the Basin Plan needs to keep these limitations in mind. In the absence of adequate data to correct for these changes over time, it has been assumed that modelled inflows include the full effect of these interceptions and unmodelled watercourse diversions and

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 43 AND BASELINE CONDITIONS Murray–Darling Basin Authority 3.3 0.0 1.7 0.8 5.5 16.3 11.1 78.1 43.9 15.7 42.4 27.7 28.8 38.2 Average 238.4 Average 3.3 0.0 0.1 0.0 2.1 13.7 10.3 78.1 35.3 15.3 42.4 27.7 17.4 19.7 2009– 2010 226.1 2009– 2010 3.3 0.0 0.1 0.2 4.2 19.0 10.3 78.1 39.7 15.3 42.4 27.7 13.6 18.1 2008– 2009 235.7 2008– 2009 3.3 0.0 0.2 0.9 4.1 19.2 10.3 78.1 44.3 15.3 42.4 27.7 12.6 17.7 2007– 2008 240.5 2007– 2008 3.3 0.0 0.4 0.9 6.8 14.0 10.0 78.1 35.8 15.6 42.4 27.7 16.7 24.8 2006– 2007 226.9 2006– 2007 3.3 0.0 0.6 0.9 18.0 11.4 78.1 44.5 15.3 42.4 27.7 60.6 17.7 79.7 2005– 2006 240.7 2005– 2006 3.3 0.0 1.0 0.9 9.2 16.7 12.3 78.1 38.8 15.3 42.4 27.7 39.4 50.5 2004– 2005 234.5 2004– 2005 3.3 0.0 1.3 0.9 9.1 18.7 10.3 78.1 44.3 15.3 42.4 27.7 23.5 34.8 2003– 2004 240.1 2003– 2004 3.3 0.0 1.8 0.9 13.7 10.3 78.1 35.3 15.3 42.4 27.7 22.5 12.8 37.9 2002– 2003 226.1 2002– 2003 3.3 0.0 4.4 0.9 5.7 15.7 12.3 78.1 50.3 16.7 42.4 27.7 23.2 34.2 2001– 2002 246.4 2001– 2002 3.3 0.0 2.5 0.9 0.0 15.7 10.3 78.1 56.3 15.6 42.4 27.7 39.3 42.7 2000– 2001 249.4 2000– 2001 3.3 0.0 2.6 0.9 0.0 15.7 14.3 78.1 51.3 16.1 42.4 27.7 41.8 45.3 1999– 2000 248.8 1999– 2000 3.3 0.0 3.2 0.9 0.0 17.7 11.3 78.1 57.3 15.9 42.4 27.7 34.4 38.5 1998– 1999 253.6 1998– 1999 3.3 0.0 3.7 0.9 0.0 13.7 11.3 78.1 38.3 16.3 42.4 27.7 29.8 34.4 1997– 1998 231.0 1997– 1998

1 Intersecting Streams diversions are partly included in the Queensland models and the estimated diversions have not been reviewed have diversions included in the Queensland models and estimated partly are diversions Streams Intersecting New South Wales New Intersecting Streams Rivers Border Gwydir Namoi/Peel Macquarie/ Castlereagh/Bogan Barwon–Darling/ Darling lower Lachlan Murrumbidgee Murray NSW Total Victoria Goulburn/Broken/ Loddon Campaspe Wimmera–Mallee Murray/Kiewa/ Ovens Victoria Total

Table 24 Diversions not included in Cap/water sharing models (GL/year) included in Cap/water not 24 Diversions Table 1

44 therefore the estimates of the total inflows The ACT diversions figure is based on the (Schedule 1 to the proposed Basin Plan) current Cap of 40.5 GL/y. are obtained by adding interceptions and unmodelled diversions to the modelled Kiewa inflows (Table 25). Kiewa inflows under without-development The BDLs are based on the sum of the conditions for the modelling period modelled diversions (as presented in have been derived using flow for Kiewa the water balance tables), unmodelled at Bandiana after correcting them with watercourse diversions (Section 5) and historical diversions data (MDBC 2002b). interceptions. Estimates of these different Since flows at Bandiana are net of river components have been included in Schedule system losses, total Kiewa inflows have 3 to the proposed Basin Plan and are also been corrected by 7 GL/y for estimated river presented in this document in Table 26. system losses. For some valleys, additional adjustments Kiewa diversions have been estimated by have been made to the inflows and MDBC at the 1993/94 level of development BDL estimates. These adjustments are as part of setting up the Cap in various shown in Table 25 and Table 26 and are valleys (MDBC 2002b). These diversions are described below. estimated as 11 GL/y.

Queensland valleys and Intersecting Streams Murray For the Paroo, Warrego, Condamine– The local inflows to the Murray are based Balonne, Nebine and Moonie systems, the on the directly and indirectly gauged Murray modelled diversions reported in Table 26 are sub-catchments and the Snowy Mountain based on the total Queensland diversions Hydro-electric Scheme releases (Table 23). only. Modelled NSW diversions in these The indirectly gauged inflows are 260.2 valleys (a total of 9 GL/y) have not been GL/y. The directly gauged inflows are 4,047.1 used because of advice from NOW on the GL/y, but this figure includes inflows to the questionable accuracy of these estimates. Kiewa of 668 GL/y and excludes contribution The NSW diversions in these regions are from the Murray catchment managed represented by Intersecting Streams, but the by the Snowy scheme estimated as 617 modelled diversions have been replaced by a GL/y. The modelled local inflows for the diversions figure of 3 GL/y, which is based on Murray exclude Kiewa inflows, as Kiewa Cap reporting (Table 26). has been reported separately (Table 25). Therefore, Murray local catchment inflows Murrumbidgee are estimated as 4,256 GL/y (4,047 gauged The Murrumbidgee inflows include + 260 ungauged – 668 Kiewa inflows a Snowy transfer of 402 GL/y. This is reported separately + 617 Murray catchment based on a transfer of 498 GL/y, which managed by the Snowy scheme). has been reduced by 96 GL/y to account The diversions reported in the water balance for water recovery under the Water for table (Table 23) provides total Murray Rivers program. diversions for NSW, Victoria and South The Murrumbidgee diversions have been Australia. The total Murray diversions in the adjusted by -44 GL/y (long-term Cap water balance table (Table 26) also includes equivalent) to account for water recovery the 55 GL/y of lower Darling diversions, through market purchase mechanisms separately reported in the proposed under the Water for Rivers program. Basin Plan.

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 45 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Ovens The Ovens model is not implemented in the IRSMF framework and was only updated to the end of December 2008 (SKM 2009b). The modelled annual average outflows for the without-development scenario is 1,735 GL/y for the period July 1895 to December 2008 (Table 15). This time series has been extended to 30 June 2009 using gauged flow data for the Ovens River at Peechelba. The resulting annual average outflows for the whole baseline period of July 1895 to June 2009 is 1,728 GL/y, which is 7 GL/y less than for the modelled period (July 1895 – Dec 2008). It is assumed that the relatively low outflows in the January to June 2009 period result from relatively low inflows in this period. Therefore, the modelled inflows of 1,753 GL/y (Table 15) have also been reduced by 7 GL/y to 1,746 GL/y (Table 25). Modelled diversions were also extended to June 2009 (based on reported annual diversions for the valley), but this did not change the overall annual average of 25.4 GL/y.

Wimmera–Avoca The without-development inflows for the Wimmera are 248 GL/y (Table 20). As the Avoca model has not been included in the modelling framework, 88 GL/y was added for Avoca inflows (taken from the Murray–Darling Basin Sustainable Yields project, CSIRO 2008g). The estimated transfer of 24.7 GL/y from the Glenelg into the Wimmera catchment has also been included in the total inflows figure, as have 22.6 GL/y of inflows from the Avon and Richardson that have been included in the baseline model, but not in the without-development model. This results in a total adjustment addition of 135 GL/y to the modelled without-development inflows (Table 25).

46 Table 25 Modelled without-development local inflows and additions/adjustments made to determine total inflows as reported in Schedule 1 to the proposed Basin Plan (GL/y) Modelled inflows (without- Unmodelled Total SDL resource unit development) diversions Interceptions Adjustments inflows Northern Basin Paroo 678 9.7 688 Warrego 616 83 699 Condamine–Balonne 1651 265 1,916 Nebine 94 25 119 Moonie 151 51 202 Intersecting Streams 111 111 Border Rivers (total)1 2,002 41 173 2,217 Gwydir 996 11 125 1,131 Namoi 1,883 78 165 2,126 Macquarie– 2,859 44 310 3,213 Castlereagh Barwon–Darling 914 914 Total northern Basin 11,844 174 1,318 0 13,336 Southern Basin Ovens 1,753 58 -7 1,804 Goulburn–Broken 3,378 29 152 3,558 (total)2 Loddon 255 90 346 Campaspe 290 2 40 332 Murrumbidgee (total) 4,236 42 513 402 5,193 Kiewa 668 14 7 689 Lower Darling 5.5 6 Murray (total) 3 4,256 33 153 527 4,968 EMLR / Marne– 1205 120 Saunders4 Total southern Basin 14,956 106 1,025 929 17,016 Disconnected Lachlan 1,424 16 316 1,755 Wimmera–Mallee 248 1 62 135 446 Total disconnected 1,672 17 378 88 2,154 Basin total 28,465 297 2,721 1,064 32,506 1 Includes Queensland Border Rivers and NSW Border Rivers SDL resource units 2 Includes Goulburn and Broken SDL resource units 3 Includes NSW Murray, Victorian Murray, SA Murray and SA Non-Prescribed Areas SDL resource units 4 Includes Eastern Mount Lofty Ranges and Marne–Saunders SDL resource units 5 Not modelled by MDBA, but based on MDBSY water availability estimate (CSIRO 2008k) Note: Reported total inflows can vary slightly from the sum of numbers in individual columns due to rounding.

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 47 AND BASELINE CONDITIONS Murray–Darling Basin Authority 9.9 31 84 83 56 128 978 114 320 303 450 508 734 198 179 153 ...continued 3,858 1,689 2,501 Total BDL Total 9.7 83 25 51 78 95 58 43 90 40 265 111 125 165 310 109 501 1,318 Interceptions

0.2 6 3 45 33 25 13 89

713 242 208 325 343 424 198 113 2,540 1,580 2,000 Total Total watercourse diversions

-6 -6 -44 Adjustments

2 25 16 11 78 44 29 42 174 Unmodelled Unmodelled diversions

0.2 6 9 45 33 25 13 89 713 218 191 314 265 380 198 111 2,372 1,552 2,002 Modelled Modelled diversions 1 1 1 Modelled diversions, unmodelled diversions and adjustments made to determine the total watercourse diversions and interceptions and interceptions diversions watercourse the total determine made to and adjustments diversions unmodelled diversions, Modelled added to determine final BDL estimates as presented in the proposed Basin Plan (GL/y) in the proposed as presented final BDL estimates determine added to 1 Paroo Warrego Condamine–Balonne1 Nebine Moonie Streams Intersecting — Queensland Rivers Border — NSW Rivers Border Gwydir Namoi Macquarie–Castlereagh Barwon–Darling northern basin Total Ovens Goulburn Broken Loddon Campaspe Murrumbidgee (NSW) SDL resource unit SDL resource Northern Basin Southern Basin Table 26 Table

48 3.5 2.9 53 25 61 28.3 665 618 129 747 1,812 1,707 9,018 13,623 Total BDL Total 5.5 3.5 12 14 45 62 104 316 378 1,025 2,721 Interceptions

2.9 40.5 11 55 28.3 67

665 302 368 1,708 1,662 7,993 10,902 Total Total watercourse diversions 2 3

2.9 0 40.5 28.3 28 22 Adjustments

6 1 28 16 16 106 297 Unmodelled Unmodelled diversions

11 55 66 665 287 352 1,680 1,657 7,858 10,583 Modelled Modelled diversions Modelled diversions, unmodelled diversions and adjustments made to determine the total watercourse diversions and interceptions and interceptions diversions watercourse the total determine made to and adjustments diversions unmodelled diversions, Modelled added to determine final BDL estimates as presented in the proposed Basin Plan (GL/y) in the proposed as presented final BDL estimates determine added to Australian Capital Territory Capital Australian Kiewa Darling Lower South Wales — New Murray — Victoria Murray — South Australia Murray areas SA non-prescribed Mount Lofty Ranges Eastern Marne–Saunders southern Basin Total Lachlan Wimmera–Mallee disconnected Total and commercial plantations and commercial Queensland diversions only Queensland diversions by runoff dams water plan which includes 13 GL/y of intercepted allocation EMLR water of the draft full realisation to corresponding Water Department for by South Australian provided Data by runoff dams water Intercepted SDL resource unit SDL resource Disconnected Basin total

Table 26 Table 1 2 3

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 49 AND BASELINE CONDITIONS Murray–Darling Basin Authority

7 PUBLISHED NUMBERS • Best available estimates for the impact of groundwater use on the river system The numbers published in this report for flows at 2030 have been included in the various water balance terms (i.e. diversions, Lachlan (17.4 GL/y), Namoi (11.2 GL/y) losses, inflows or end-of-system flows) and Murray (47 GL/y) models. for various catchments may be different • Some model calibrations have been to those published previously in reports improved since the versions used for the by MDBA, the Basin states, CSIRO or development of various water sharing other consultants for the purposes of the arrangements in the past and these Cap or water sharing plans/ROPs/bulk updated models have been used for the entitlements. There are number of reasons Basin planning purposes. why these could be different and these reasons vary from valley to valley. The key More details on the differences between reasons for the differences are as follows. previously published numbers and the • The Basin Plan modelling has been numbers presented here can be found in a undertaken using the climatic data for separate report (MDBA 2011). the period July 1895 to June 2009. This was the common period for which all 24 river system models had climate data available. Numbers published by MDBA, states, CSIRO or consultants for various river systems are not for this period and usually results are based on the longest period for which data was available for individual river systems. • Models were updated to include permanent inter- and intra-state water trade. • Models were updated to include water recovered by TLM and Water for Rivers (for provision of environmental flows to the Snowy and Murray rivers) and its use for the environmental works and measures. • Any improvements or updating of models carried by the states/MDBA since the development of water sharing plans in NSW, water resource plans/ ROPs in Queensland or bulk entitlement in Victoria were adopted in the Basin Plan version of models.

50 8 REFERENCES Bewsher, D 2011b, Wimmera–Mallee Valley Independent Audit of Cap Model, Prepared Bewsher, D 2002a, Gwydir Valley for the Murray–Darling Basin Authority, Independent Audit of Cap Model, Bewsher Consulting Ltd. Prepared for the Murray–Darling Basin Commission, Bewsher Consulting Chiew FHS, Cai W and Smith IN 2009a, Pty Ltd. Advice on defining climate scenarios for use in the Murray–Darling Basin Authority Bewsher, D 2002b, Lachlan Valley Basin Plan modelling, CSIRO report for Independent Audit of Cap Model, the Murray–Darling Basin Authority. Prepared for the Murray–Darling Basin Commission, Bewsher Consulting Chiew FHS, Teng J, Vaze J, Post DA, Pty Ltd. Perraud J-M, Kirono DGC and Viney NR 2009b, Estimating climate change Bewsher, D 2005, Namoi Valley, Independent impact on runoff across south- Audit of Cap Model, Prepared for the east Australia: method, results and Murray–Darling Basin Commission, implications of modelling method. Bewsher Consulting Pty Ltd. Water Resources Research, 45, W10414, Bewsher, D 2006, Goulburn/Broken/Loddon doi:10.1029/2008WR007338. and Campaspe valleys, Independent Chiew FHS, Teng J, Kirono D, Frost AJ, Audit of Cap Model, Prepared for the Bathols JM, Vaze J, Viney NR, Young Murray–Darling Basin Commission, WJ, Hennessy KJ and Cai WJ 2008a, Bewsher Consulting Pty Ltd. Climate data for hydrologic scenario Bewsher, D 2008, Victorian Murray, NSW modelling across the Murray–Darling Murray and Lower Darling valleys, Basin, A report to the Australian Independent Audit of Cap Model, Government from the CSIRO Murray– Prepared for the Murray–Darling Basin Darling Basin Sustainable Yields Project. Commission, Bewsher Consulting Ltd. CSIRO, Australia, 42 pp. (ISSN 1835- 095X), http://www.csiro.au/resources/ Bewsher, D 2009, Peel Valley IQQM HydrologicScenarioModellingMDBSY. Independent Audit of Cap Model, Prepared html. for the Murray–Darling Basin Authority, Bewsher Consulting Ltd. Chiew FHS, Vaze J, Viney NR, Jordan PW, Perraud J-M, Zhang L, Teng J, Young Bewsher, D 2010a, Paroo, Warrego, WJ, Penaarancibia J, Morden RA, Nebine and Moonie Valleys, Independent Freebairn A, Austin J, Hill PI, Wiesenfeld Audit of Cap Models, Prepared for CR and Murphy R 2008b, Rainfall-runoff the Murray–Darling Basin Authority, modelling across the Murray–Darling Bewsher Consulting Pty Ltd. Basin, A report to the Australian Bewsher, D 2010b, Murrumbidgee Valleys, Government from the CSIRO Murray– Independent Audit of Cap Models, Darling Basin Sustainable Yields Project. Prepared for the Murray–Darling Basin CSIRO, Australia, 70 pp. (ISSN 1835- Authority, Bewsher Consulting Pty Ltd. 095X), http://www.csiro.au/resources/ Bewsher, D 2011a, Macquarie Valley, Rainfall-runoffModellingMDBSY.html. Independent Audit of Cap Model, Commonwealth of Australia 2007, Water Act. Prepared for the Murray–Darling Basin An up-to-date electronic compilation Commission, Bewsher Consulting of this Act is available at http://www. Pty Ltd. comlaw.gov.au.

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 51 AND BASELINE CONDITIONS Murray–Darling Basin Authority

CSIRO and Australian Bureau of CSIRO 2008d, Water availability in the Meteorology 2007, Climate Change in Goulburn–Broken, A report to the Australia. Technical report. http//www. Australian Government from the CSIRO climatechangeinaustralia.gov.au. Murray–Darling Basin Sustainable Yields Project. CSIRO, Australia. 132pp. CSIRO 2007a, Water availability in the Border Rivers, A report to the Australian CSIRO 2008e, Water availability in the Gwydir, Government from the CSIRO Murray– A report to the Australian Government Darling Basin Sustainable Yields Project. from the CSIRO Murray–Darling Basin CSIRO, Australia. 144pp. Sustainable Yields Project. CSIRO, Australia. 134pp. CSIRO 2007b, Water availability in the Namoi, A report to the Australian Government CSIRO 2008f, Water availability in the from the CSIRO Murray–Darling Basin Lachlan, A report to the Australian Sustainable Yields Project. CSIRO, Government from the CSIRO Murray– Australia. 154pp. Darling Basin Sustainable Yields Project. CSIRO, Australia. 133pp. CSIRO 2007c, Water availability in the Paroo, A report to the Australian Government CSIRO 2008g, Water availability in the from the CSIRO Murray–Darling Basin Loddon–Avoca, A report to the Australian Sustainable Yields Project. CSIRO, Government from the CSIRO Murray– Australia. 88pp. Darling Basin Sustainable Yields Project. CSIRO, Australia. 132pp. CSIRO 2007d, Water availability in the Warrego, A report to the Australian CSIRO 2008h Water availability in the Government from the CSIRO Murray– Macquarie–Castlereagh, A report to the Darling Basin Sustainable Yields Project. Australian Government from the CSIRO CSIRO, Australia. 89pp. Murray–Darling Basin Sustainable Yields Project. CSIRO, Australia. 144pp. CSIRO 2007e, Water Availability in the Wimmera, A report to the Australian CSIRO 2008i, Water availability in the Moonie, Government from the CSIRO Murray– A report to the Australian Government Darling Basin Sustainable Yields Project. from the CSIRO Murray–Darling Basin CSIRO, Australia. 108pp. Sustainable Yields Project. CSIRO, Australia. 79pp. CSIRO 2008a, Water availability in the Barwon–Darling, A report to the CSIRO 2008j, Water Availability in the Murray, Australian Government from the CSIRO A report to the Australian Government Murray–Darling Basin Sustainable Yields from the CSIRO Murray–Darling Basin Project. CSIRO, Australia. 106pp. Sustainable Yields Project. CSIRO, Australia. 217pp. CSIRO 2008b, Water availability in the Campaspe, A report to the Australian CSIRO 2008k, Water Availability in the Government from the CSIRO Murray– Murray–Darling Basin, A report from Darling Basin Sustainable Yields Project. CSIRO to the Australian Government. CSIRO, Australia. 120pp. CSIRO, Canberra, Australia. CSIRO, Australia. 67pp. CSIRO 2008c, Water Availability in the Condamine–Balonne, A report to the CSIRO 2008l, Water Availability in the Australian Government from the CSIRO Murrumbidgee, A report to the Australian Murray–Darling Basin Sustainable Yields Government from the CSIRO Murray– Project. CSIRO, Australia. 169pp. Darling Basin Sustainable Yields Project. CSIRO, Australia. 155pp.

52 CSIRO 2008m, Water availability in the Ovens, DERM 2008b, Moonie Resource Operations A report to the Australian Government Plan, Department of Natural Resources from the CSIRO Murray–Darling Basin & Mines, Queensland, Reprinted as in Sustainable Yields Project. CSIRO, Force on February 2006. Australia. 100pp. DERM 2010, Condamine and Balonne DECCW 2010, Water Sharing Plan for the Peel Resource Operations Plan, Department of Valley Regulated, Unregulated, Alluvium Natural Resources & Mines, December and Fractured Rock Water Sources 2010, 2008 as Amended April 2010 Revision 2. NSW Office of Water, Department of DIPNR 2004a, A Guide to the Water Sharing Environment, Climate Change and Water, Plan for the Gwydir Regulated River Water Sydney, NSW. Source, Department of Infrastructure, DERM 2006a, Warrego, Paroo, Bulloo and Planning and Natural Resources, NSW. Nebine, Resource Operations Plan, DIPNR 2004b, Water Sharing Plan for the Department of Natural Resources & Macquarie and Cudgegong Regulated Mines, Queensland. Rivers Water Source 2003. Effective 1 DERM 2006b, Paroo River Daily IQQM July 2004 and ceases ten years after ROP Scenario Modelling Description, that date. Department of Infrastructure, System Hydrology Reports (Water Planning and natural resources, Sydney. Resource Plan), prepared by Surface NSW Government Gazette. Water Assessment Group for Resource Management, Department of Natural DIPNR 2004c, Water Sharing Plan for the Resources & Mines, Queensland. Castlereagh River above Binnaway Water Source 2003. Effective 1 July 2004 DERM 2006c, Warrego River Daily IQQM and ceases ten years after that date. ROP Scenario Modelling Description, Department of Infrastructure, Planning System Hydrology Reports (Water and natural resources, Sydney. NSW Resource Plan), prepared by Surface Government Gazette. Water Assessment Group for Resource Management, Department of Natural DIPNR 2004d, Namoi River Valley IQQM Resources & Mines, Queensland. Cap Implementation Summary Report, Department of Infrastructure, Planning DERM 2006d, Moonie River Daily IQQM and Natural Resources, Sydney NSW. ROP Scenario Modelling Description, System Hydrology Reports (Water DIPNR 2004e, A guide to the Water Sharing Resource Plan), prepared by Surface Plan for the Lachlan Regulated River Water Water Assessment Group for Resource Source, Department of Infrastructure, Management, Department of Natural Planning and Natural Resources, NSW. Resources & Mines, Queensland. DIPNR 2004f, A guide to the water sharing DERM 2006e, Nebine System Daily IQQM plan for the Murrumbidgee Regulated ROP Scenario Modelling Description, River Water Source, Department of System Hydrology Reports (Water Infrastructure, Planning and Natural Resource Plan), prepared by Surface Resources, NSW. Water Assessment Group for Resource DIPNR 2004g, A guide to the water sharing Management, Department of Natural plan for the Upper Namoi and Lower Resources & Mines, Queensland. Namoi Regulated River Water Sources, DERM 2008a, Cap proposal for the Border Department of Infrastructure, Planning Rivers valley, Department of Natural and Natural Resources, NSW. Resources & Mines, Queensland.

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 53 AND BASELINE CONDITIONS Murray–Darling Basin Authority

DLWC 1995, Integrated Quantity-Quality Hameed T and Podger G 2001, Use of Model (IQQM) Reference Manual, IQQM Simulation Model for Planning NSW Department of Land & Water and Management of a Regulated Conservation, Report No. TS94.048. River System. In: Integrated Water Resources Management (Proceedings of DLWC 2002, Lachlan River Valley IQQM a symposium held at Davis, California in Cap implementation Summary report, April 2000). IAHS Publ. no. 272, 2001. NSW Department of Land and Water Conservation. IPCC 2007, Climate Change 2007: The Physical Basis. Contributions of Working DNR 2006a, Barwon–Darling River Valley Group 1 to the Fourth Assessment IQQM Implementation Calibration Report of the Intergovernmental Summary Report, Water Management Panel on Climate Change. Cambridge Division, NSW Department of University Press. http://www.ipcc.ch. Natural Resources. MDBA 2009, Review of Cap Implementation DNR 2006b, Macquarie River Valley IQQM 2008-09. MDBA Publication No. 45/09. Cap Implementation Summary Report, New South Wales, Department of MDBA 2010a, Basin Plan Model Linkages, Natural Resources. Murray–Darling Basin Authority, Technical Report 2010/18. DNR 2006c, Peel River Valley IQQM Cap Implementation Summary Report, NSW MDBA 2010b, Guide to the proposed Basin Department of Natural Resources. Plan: Overview, Murray–Darling Basin Authority, Canberra. MDBA Publication DNR 2009, Gwydir River Valley IQQM Cap no 60/10. Implementation Summary Report, Department of Natural Resources, NSW. MDBA 2011, Comparison of Watercourse Diversions Estimates in the proposed DSE 2005, Goulburn Simulation Model Basin Plan with other Published Estimates, — Calibration for the Murray–Darling Murray–Darling Basin Authority, Basin Cap, Victorian Department of Technical Report 2011/01 – version 2. Sustainability and Environment. MDBC 2002a, Setting up of MSM-BIGMOD DSE 2007, Upgrade of Campaspe Valley modelling Suite for the River Murray cap model, Victorian Department of System, Murray–Darling Basin Sustainability and Environment. Commission, MDBC Technical Report DSE 2010, Victorian Water Register, Victorian 2002/5. Department of Sustainability and MDBC 2002b, Derivation of Kiewa Catchment Environment, http://www.waterregister. Inflows, MDBC Technical Report 2002/6. vic.gov.au/Default.aspx, Last accessed October 2010. MDBC 2006a, Review of the Interim Operating Rules for the Barmah–Millewa Forest DWE 2007, Murrumbidgee River Valley IQQM Environmental Water Allocation: Part 1, Cap Implementation Summary Report MDBC Technical Report No. 2006/4. (Draft), NSW Department of Water and Energy. MDBC 2006b, Revised Operating Rules for the Barmah–Millewa Forest Environmental DWE 2009, Water Sharing in the Water Allocation, MDBC Technical Report Murrumbidgee Regulated River Progress No. 2006/13. Report 2004 to 2008, NSW Department of Water and Energy.

54 MDBC 2007, Setting up of the Murray In: 18th World IMACS Congress and Simulation Model (MSM) for Auditing the MODSIM09 International Congress on CAP in the Murray and Lower Darling Modelling and Simulation, Modelling and River Systems, Murray–Darling Basin Simulation Society of Australian and New Commission, Technical Report No. Zealand and International Association 2006/11. for Mathematics and Computers in Simulation, Cairns, July 2009, http:// Perera BJC and James B 2003, A www.mssanz.org.au/modsim09, (ISBN Generalised Water Supply Simulation 978-0-9758400-7-8), pp. 3421–3427. Computer Software Package, Hydrology Journal, 26, 67-83. WAMC 2002, Snowy Water Licence, Issued under Part 5 of the Snowy Post DA, Chiew FHS, Vaze J, Teng J Hydro Corporatisation ACT 1997 and Perraud JM 2008, Future runoff (NSW). Available at: http://www. projections (~2030) for southeast Australia. naturalresources.nsw.gov.au/water/pdf/ South Eastern Australian Climate Initiative lic_snowy_water_licence.pdf Report, 32 pp. http://www2.mdbc.gov. au/subs/seaci/docs/reports/SEACI_ Webster IT 2007, Hydrodynamic Modelling of RunoffProjections.pdf. the Coorong, Water for a Healthy Country National Research Flagship, CSIRO. SKM 2007, Projections of effect of future farm dam development to the year 2030 on W&D 2009, Murray–Darling Basin Cap runoff, unpublished report to the CSIRO Model Accreditation Submission — Murray–Darling Basin Sustainable Yields Wimmera-Mallee Cap River Valley, Project, CSIRO, Canberra. W&D Engineering and Legal Services, Grampians Wimmera Mallee Water SKM, CSIRO & BRS 2010, Surface and/or Corporation (GWMWater). groundwater interception activities: initial estimates, Waterlines report, Series Yang, A 2010, The Integrated River System No. 30, National Water Commission, Modelling Framework. A report to the Canberra Murray–Darling Basin Authority. CSIRO: Water for a Healthy Country National SKM 2008, Ovens REALM Model Review — Research Flagship, Canberra. Model review and revision report, Sinclair Knight Merz. SKM 2009a, Goulburn Simulation Model Update of Inputs 2009, Sinclair Knight Merz. SKM 2009b, Ovens River REALM model, 2009 Update of Inputs. Sinclair Knight Merz. Vaze J, Chiew FHS, Perraud JM, Viney NR, Post DA, Teng J, Wang B, Lerat J and Goswami M 2010, Rainfall-runoff modelling across southeast Australia: datasets, models and results. Submitted. Viney NR, Perraud J, Vaze J, Chiew FHS, Post DA and Yang A 2009, The usefulness of bias constraints in model calibration for regionalisation to ungauged catchments.

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 55 AND BASELINE CONDITIONS 9 APPENDIX Legend: Modelled annual average inflows, Inflows diversions, losses (including change Diversions in storage) and end-of-system flows Losses (i.e. flow to downstream system) (GL/y) for without-development and End-of-system flow baseline scenarios.

Paroo Condamine Balonne 700 1,800 1,600 600 1,400 500 1,200 400 I 1,000 I D 800 D 300 L 600 L 200 O O 400 100 200 0 0 WO DevelopmentBaseline WO DevelopmentBaseline

Warrego Moonie 700 160

600 140 120 500 100 400 I I 80 D D 300 L 60 L 200 O 40 O 100 20

0 0 WO DevelopmentBaseline WO Development Baseline

Nebine Border Rivers 100 2,100 90 1,800 80 70 1,500

60 I 1,200 I 50 D D 900 40 L L 30 600 O O 20 300 10 0 0 WO DevelopmentBaseline WO Development Baseline Gwydir Lachlan

1,000 1,400 1,200 800 1,000 I I 600 800 D D 600 400 L L 400 O O 200 200

0 0 WO DevelopmentBaseline WO DevelopmentBaseline

Namoi Murrumbidgee 2,000 5,000 1,800 4,500 1,600 4,000 1,400 3,500 1,200 I 3,000 I 1,000 2,500 D D 800 2,000 L L 600 1,500 O O 400 1,000 200 500 0 0 WO DevelopmentBaseline WO DevelopmentBaseline

Macquarie-Castlereagh Ovens 3,000 1,800 1,600 2,500 1,400

2,000 1,200 I 1,000 I 1,500 D 800 D

1,000 L 600 L O 400 O 500 200

0 0 WO DevelopmentBaseline WO DevelopmentBaseline

Barwon-Darling Goulburn-Broken 4,500 3,500

4,000 3,000 3,500 2,500 3,000 2,500 I 2,000 I D 2,000 D 1,500 1,500 L L 1,000 1,000 O O 500 500 0 0 WO DevelopmentBaseline WO DevelopmentBaseline

WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 57 AND BASELINE CONDITIONS Murray–Darling Basin Authority

Campaspe Wimmera 300 300

250 250

200 200 I I 150 150 D D

100 L 100 L O O 50 50

0 0 WO DevelopmentBaseline WO DevelopmentBaseline

Loddon Murray 280 18,000 16,000 240 14,000 200 12,000 160 I 10,000 I D D 120 8,000 L 6,000 L 80 O 4,000 O 40 2,000

0 0 WO DevelopmentBaseline WO DevelopmentBaseline

58 WATER RESOURCE ASSESSMENTS FOR WITHOUT-DEVELOPMENT 59 AND BASELINE CONDITIONS

Errata to Murray-Darling Basin Authority Technical Report 2010/20 – versions 2: ‘Water Resource Assessments for Without Development and Baseline Conditions’

Errata to Table 25 in the original report:

 Total Modelled Inflows for the Basin are 28472 GL/y, instead of 28465 GL/y.  Unmodelled diversions for Border Rivers should be 41 GL/y, instead of 415 GL/y.  Total adjustments for the disconnected system (Lachlan and Wimmera) should be 135 GL/y, instead of 88 GL/y  Total inflows for the disconnected system (Lachlan and Wimmera) should be 2201 GL/y, instead of 2154 GL/y  Total inflows for the whole basin should be 32553 GL/y, instead of 32506 GL/y  Footnote (3) for Murrumbidgee (Total) should indicate that this includes the Murrumbidgee and ACT SDL resource units.  Text for footnote 3 refers to Murray (Total), not Murrumbidgee (Total).

A corrected version of the table is provided on the following page.

Table 1 Modelled Without Development Local Inflows and Additions/Adjustments made to determine Total Inflows as reported in Schedule 1 of the Proposed Basin Plan (GL/y) – Corrected version.

Modelled inflows (without Unmodelled Intercep- Adjust- Total SDL resource unit development) diversions tions ments Inflows Northern Basin Paroo 678 9.7 688 Warrego 616 83 699 Condamine-Balonne 1651 265 1916 Nebine 94 25 119 Moonie 151 51 202 Intersecting Streams 111 111 Border Rivers (Total)(1) 2002 41 173 2217 Gwydir 996 11 125 1131 Namoi 1883 78 165 2126 Macquarie-Castlereagh 2859 44 310 3213 Barwon-Darling 914 914 Total Northern Basin 11844 174 1318 0 13336 Southern Basin Ovens 1753 58 -7 1804 Goulburn-Broken (Total)(2) 3378 29 152 3558 Loddon 255 90 346 Campaspe 290 2 40 332 Murrumbidgee (Total)(3) 4236 42 513 402 5193 Kiewa 668 14 7 689 Lower Darling 5.5 6 Murray (Total)(4) 4256 33 153 527 4968 EMLR / Marne-Saunders(5) 120 120 Total Southern Basin 14956 106 1025 929 17016 Disconnected Lachlan 1424 16 316 1755 Wimmera-Mallee 248 1 62 135 446 Total Disconnected 1672 17 378 135 2201 Basin Total 28472 297 2721 1064 32553 (1) Includes Queensland Border Rivers and NSW Border Rivers SDL resource units (2) Includes Goulburn and Broken SDL resource units (3) Includes Murrumbidgee and ACT SDL resource units (4) Includes NSW Murray, Victorian Murray, SA Murray and SA Prescribed Areas SDL resource units (5) Includes Eastern Mount Lofty Ranges and Marne-Saunders SDL resource units Note: Reported Total Inflows can vary slightly from the sum of numbers in individual columns due to rounding